利用反射實現對sqlite3資料庫的crud(增刪改查)操作的一個baseAndroidDao封裝,安卓開發中
阿新 • • 發佈：2019-02-08
1.說明
博主主要是做java web後臺這一塊,但是偶爾做點安卓,發現安卓上沒有像Hibernate這種orm框架(....其實也沒有去找),
又覺得每次增刪改查都自己寫程式碼的話肯定是非常麻煩的,所以就寫了一個簡單的baseAndroidDao來封裝一些簡單的增刪改查操作;
需要注意的是,此框架並非一個健全的orm框架,功能簡單,而且這些功能必須採用博主約定的方式才能正確執行;
2.具體實現
例舉現在有一個javaBean如下,其如同Hibernate中的實體,但是卻只是通過屬性來存取值(博主嫌麻煩....沒有用getter和setter那種標準方式,而且基本夠用...)
public class User extends BaseEntity { public Long Id; public String Login_Name; public String Password; public String Real_Name; public Long State; public String Uid; @Entity_FieldProperty(FieldType=FieldType.JsonObject,cls=Sys_User_Info.class) public Sys_User_Info UserInfo; @Override public Long getId() { return Id; } }
約定一:所有實體(用來儲存和資料庫表資料相對應的bean)必須繼承BaseEntity類,
約定二:同時屬性的名稱必須和資料庫中的欄位相一致;不過,主鍵必須是Long Id(不區分大小寫),資料庫中將會以_id欄位儲存;
約定三:只支援Boolean,Date,Long,String,Integer,List,Objec,Float,Double這幾個包裝類的屬性,不支援陣列型別;
約定四.通過Entity_FieldProperty註解來實現對List,bean物件,靜態物件的控制;
說明:這些約定都是很好改的.....如有需要可以下載之後自己該,最好是改成類似Hibernate那種註解識別id的方式,然後給博主發一份過來嘿嘿;
其中BaseEntity主要是封裝一些對Entity的操作....具體程式碼如下(其實這些東東封裝到Dao中,然後用Dao對Entity操作時最好的,這樣Entity也不用繼承BaseEntity)
以後有時間博主會重寫結構然後更新(現在結構很垃圾..耦合重...),但是利用反射的核心程式碼不會這麼變,所以大家可以看看:
/** * Entity約定: * 0.主鍵的名稱必須是id,不分大小寫,資料庫中以_id儲存 * 1.只支援Boolean,Date,Long,String,Integer,List,Objec,Float,Double這幾個包裝類的屬性,不支援陣列型別 * 2.其它屬性的值,不支援自動賦值與使用 * 3.通過Entity_FieldProperty註解來實現對List,bean物件,靜態物件的控制; * @author dview * */ public abstract class BaseEntity { /** * 下面規定允許的資料型別 */ @JSONField(serialize=false) private final String type_boolean="class java.lang.Boolean", type_date="class java.util.Date", type_float="class java.lang.Float", type_double="class java.lang.Double", type_long="class java.lang.Long", type_integer="class java.lang.Integer", type_string="class java.lang.String"; @JSONField(serialize=false) public final static String primaryKeyName="_id"; /** * 判斷一個屬性是否是靜態變數,此類暫時不用 * @param field */ @JSONField(serialize=false) public boolean isStaticField(Field field){ boolean isStatic = Modifier.isStatic(field.getModifiers()); return isStatic; } /** * 為本實體類賦值 * @throws IllegalArgumentException * @throws IllegalAccessException */ @JSONField(serialize=false) private void setFieldValue(Cursor c) throws IllegalAccessException, IllegalArgumentException{ if(c==null) return; Class<?> clazz=this.getClass(); Field[] fs=clazz.getDeclaredFields(); for(Field f:fs){ int index=0;//cursor遊標中的索引,某個欄位 try{ f.setAccessible(true);//強制獲取,設定值 Annotation[] as=f.getAnnotations(); Class<?> fclass=null; FieldType fType=null; for(int i=0;i<as.length;i++){ Annotation a=as[i]; if(a instanceof Entity_FieldProperty){ Entity_FieldProperty ef=(Entity_FieldProperty)a; if(ef!=null){ fclass=ef.cls(); fType=ef.FieldType(); } break; } } String typeString=f.getGenericType().toString(); String name=f.getName(); if(name.toLowerCase(Locale.ENGLISH).equals("id")) { name=primaryKeyName; } index=c.getColumnIndex(name); if(index==-1) continue; //按照基礎六類屬性來處理 if(fType==null||fType==FieldType.Base){ if(typeString.equals(type_boolean)){ int result=c.getInt(index); f.set(this, (Boolean)(result==1)); }else if(typeString.equals(type_date)){ Long m=c.getLong(index); if(m!=null) { f.set(this, new Date(m)); }else{ f.set(this,null); } }else if(typeString.equals(type_integer)){ f.set(this,c.getInt(index)); }else if(type_long.equals(typeString)){ f.set(this,c.getLong(index)); }else if(typeString.equals(type_float)){ f.set(this,c.getFloat(index)); }else if(typeString.equals(type_double)){ f.set(this,c.getDouble(index)); }else{ f.set(this,c.getString(index)); } }else if(fType==FieldType.Transient){ continue; }else if(fType==FieldType.JsonObject){ Object jobj=null; if(c.getString(index)!=null) JsonUtils_wg.parseToObject(c.getString(index), fclass); f.set(this,jobj); }else if(fType==FieldType.JsonList){ List<?> objs = null; if(c.getString(index)!=null) objs=JsonUtils_wg.parseToArray(c.getString(index), fclass); f.set(this,objs); } } catch (Exception e) { Log.e(this.getClass().getName(), e.toString()); e.printStackTrace(); continue; }//end try }//end for } /** * 以鍵值對的方式,返回單籤類的,屬性的名稱和之所對應的值 * @return * @param isChangeIdString 是否改變屬性名稱為id的鍵為BaseEntity.primaryKeyName所代表的屬性值 * @throws IllegalArgumentException * @throws IllegalAccessException */ @JSONField(serialize=false) private Map<String,Object> getFieldValue(boolean isChangeIdString) throws IllegalAccessException, IllegalArgumentException{ Map<String,Object> maps=new HashMap<String,Object>(); Class<?> clazz=this.getClass(); Field[] fs=clazz.getDeclaredFields(); for(Field field:fs){ field.setAccessible(true); Annotation[] as=field.getAnnotations(); Class<?> fclass=null; FieldType fType=null; for(int i=0;i<as.length;i++){ Annotation a=as[i]; if(a instanceof Entity_FieldProperty){ Entity_FieldProperty ef=(Entity_FieldProperty)a; if(ef!=null){ fclass=ef.cls(); fType=ef.FieldType(); } break; } } String typeString=field.getGenericType().toString(); String name=field.getName(); if(name.toLowerCase(Locale.ENGLISH).equals("id")&&isChangeIdString) { name=primaryKeyName; } //按照基礎六類屬性來處理 if(fType==null||fType==FieldType.Base){ if(field.get(this)==null){ maps.put(name, null); }else if(typeString.equals(type_boolean)){ if((Boolean)field.get(this)) { maps.put(name,1); } else{ maps.put(name,0); } }else if(typeString.equals(type_date)){ Date d=(Date) field.get(this); maps.put(name, d.getTime()); }else { maps.put(name,field.get(this)); } }else if(fType==FieldType.Transient){ continue; }else if(fType==FieldType.JsonObject){ if(field.get(this)==null) { maps.put(name,"{}"); }else{ String jsonString=JSON.toJSONString(field.get(this)); maps.put(name,jsonString); } }else if(fType==FieldType.JsonList){ if(field.get(this)==null) { maps.put(name,"[]"); }else{ String jsonString=JSON.toJSONString(field.get(this)); maps.put(name,jsonString); } } } return maps; } //通過Cursor自動將值賦值到實體 @JSONField(serialize=false) public void initFromCursor(Cursor c) throws IllegalAccessException, IllegalArgumentException{ setFieldValue(c); } @JSONField(serialize=false) public ContentValues getContentValues() throws IllegalAccessException, IllegalArgumentException { ContentValues cv; cv=new ContentValues(); Map<String,Object> maps=getFieldValue(true); Set<String> keys=maps.keySet(); for(String s:keys){ try{ Object obj=maps.get(s); String typeString=obj.getClass().getName(); if(obj==null){ cv.put(s,""); }else if(typeString.equals(type_boolean)){ cv.put(s,(Boolean)(obj)); }else if(typeString.equals(type_date)){ cv.put(s,((Date)(obj)).getTime()); }else if(typeString.equals(type_integer)){ cv.put(s,(Integer)(obj)); }else if(type_long.equals(typeString)){ cv.put(s,((Long)(obj))); }else if(typeString.equals(type_float)){ cv.put(s,(Float)(obj)); }else if(typeString.equals(type_double)){ cv.put(s,(Double)(obj)); }else if(typeString.equals(type_string)){ cv.put(s,(String)(obj)); }else{ cv.put(s,JSON.toJSONString(obj)); } } catch (Exception e) { Log.e(this.getClass().getName(), e.toString()); e.printStackTrace(); continue; } }//end for return cv; } /** * 返回該類屬性的鍵值對,鍵和值均為String型別 * @return * @throws IllegalAccessException * @throws IllegalArgumentException */ @JSONField(serialize=false) public Map<String,Object> getMapValues() throws IllegalAccessException, IllegalArgumentException { return getFieldValue(false); } @JSONField(serialize=false) public void saveToDataBase(String tableName,SQLiteDatabase db) throws Exception{ if(getId()==0) throw new Exception("儲存的_id號碼不能夠是0,請稍後再試!"); Map<String,Object> maps=getFieldValue(true); Set<String> keys=maps.keySet(); Object[] objs=new Object[keys.size()]; String q=""; String sql="insert into "+tableName.trim()+"("; int i=0; for(String s:keys){ Object obj=maps.get(s); if(i!=0) { sql+=","; q+=","; } sql+=s; q+="?"; objs[i]=obj; i++; } sql+=") values ("+q+")"; db.execSQL(sql, objs); } @JSONField(serialize=false) public void updateToDataBase(String tableName,SQLiteDatabase db) throws Exception{ if(getId()==0) throw new Exception("更新的_id號碼不能夠是0,請稍後再試!"); this.updateToDataBaseByColumn(tableName, db, primaryKeyName); } /** * * @param tableName * @param db * @param columnName 指定此此表的一個列名稱,更新所有相同的記錄 * @throws Exception */ @JSONField(serialize=false) public void updateToDataBaseByColumn(String tableName,SQLiteDatabase db,String columnName) throws Exception{ if(columnName==null) throw new Exception("更新的columnName不能夠是null,請稍後再試!"); Map<String,Object> maps=getFieldValue(true); Set<String> keys=maps.keySet(); Object[] objs=new Object[keys.size()+1]; String sql="update "+tableName.trim()+" set "; int i=0; for(String s:keys){ Object obj=maps.get(s); if(i!=0) { sql+=","; } sql+=s+"=?"; objs[i]=obj; if(s.equals(columnName)){ objs[keys.size()]=obj; } i++; } sql=sql+" where "+columnName+"=?"; db.execSQL(sql, objs); //data.close(); } /** * * @param tableName * @param data * @param notUpdateColumns 不需要跟新的欄位,區分大小寫 * @throws Exception */ @JSONField(serialize=false) public void updateToDataBase(String tableName,SQLiteDatabase db,String[] notUpdateColumns) throws Exception{ if(getId()==0) throw new Exception("更新的_id號碼不能夠是0,請稍後再試!"); Map<String,Object> maps=getFieldValue(true); Set<String> keys=maps.keySet(); Object[] objs; Map<String,Object> updateMap=new HashMap<String,Object>(); String sql="update "+tableName.trim()+" set "; int i=0; for(String s:keys){//篩選出來需要更新的資料 boolean need=true; if(notUpdateColumns!=null) for(String c:notUpdateColumns){ if(c.equals(s)) { need=false; break; } } if(need){ updateMap.put(s,maps.get(s)); } } Set<String> key=updateMap.keySet(); objs=new Object[key.size()+1]; i=0; for(String s:key){ Object value=updateMap.get(s); if(i!=0) { sql+=","; } sql+=s+"=?"; objs[i]=value; if(s.equals(primaryKeyName)) { objs[key.size()]=value; } i++; } sql=sql+" where "+primaryKeyName+"=?"; db.execSQL(sql, objs); } @Override public boolean equals(Object o) { if(this.getClass().getName().equals(o.getClass().getName())&&this.getId()-((BaseEntity)o).getId()==0) return true; return super.equals(o); } @Override public int hashCode() { return getId().intValue(); } public abstract Long getId(); }
其中Entity_FieldProperty這個註解主要是幫助我們對物件和List進行儲存以及讀取,說白了就是簡單的將之轉化為json字串,然後進行相關的序列號與反序列化;
/**
* 指定當前Entity中的屬性的屬性,即自生的類別和轉換的方式
* @author dview76
* 當FieldType.Base的時候,將會按照預設識別的型別使用,即此時的cls屬性不會生效
* JsonList,JsonObject,Base,Transient
* JsonList,JsonObject表示此物件需要轉換為一個json物件或者字串;
* Transient表示此物件,不進行資料庫的存和取操作,選擇Transient的時候,cls屬性不會生效
*/
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface Entity_FieldProperty {
/**
* 指定一個型別是FieldType的,表現為FieldType=預設為FieldType.Base的Annotation
* @return
*/
FieldType FieldType() default FieldType.Base;
/**
* 指定一個型別是Class的,表現為cls=預設為String.class的Annotation
* @return
*/
Class cls() default String.class;
/**
* 指定當前屬性的型別
*
*/
public enum FieldType{
JsonList,JsonObject,Base,Transient;
};
}之後是主角BaseAndroidDao,其實就是增刪改查方法的封裝:
約定如下:此dao中不會管理事務;
/**
* Dao中不會管理事務,事務在Service層中進行管理
* @author dview
*
*/
public class BaseAndroidDao<T extends BaseEntity> {
private String tableName;
private DataBaseManager dbManager;
public BaseAndroidDao(String tableName) {
super();
this.dbManager=DataBaseManager.getInstance();
this.tableName = tableName;
}
public SQLiteDatabase openDataBase(){
return dbManager.openDatabase();
}
public void closeDataBase(){
dbManager.closeDatabase();
}
/**
* 得到當前的最大的id號碼的值
* @param db
* @return
*/
public Long getMaxId(SQLiteDatabase db){
Cursor c=null;
c=this.getCursor(db,tableName,null,"select max("+T.primaryKeyName+") ", null,null,null,null,null);
if(c.moveToNext()){
return c.getLong(c.getColumnIndex(T.primaryKeyName));
}else return null;
}
/**
* 得到當前的最小的id號碼的值
* @param db
* @return
*/
public Long getMinId(SQLiteDatabase db){
Cursor c=null;
c=this.getCursor(db,tableName,null,"select min("+T.primaryKeyName+") ", null,null,null,null,null);
if(c.moveToNext()){
return c.getLong(0);
}else return null;
}
/**
* 得到當前的的記錄總數
* @param db
* @return
*/
public Long getCount(SQLiteDatabase db){
Cursor c=null;
c=this.getCursor(db,tableName,null,"select count(*) ", null,null,null,null,null);
if(c.moveToNext()){
return c.getLong(0);
}else return null;
}
/**
* 返回所儲存到資料庫中的列表
* @param entity
* @return
*/
protected List<String> getEntityColumnNameList(Class<?> cls){
List<String> list=new ArrayList<String>();
Class<?> clazz=cls;
Field[] fs=clazz.getDeclaredFields();
String filedName=null;
for(Field field:fs){
field.setAccessible(true);
filedName=field.getName();
Annotation[] as=field.getAnnotations();
Class fclass=null;
FieldType fType=null;
for(int i=0;i<as.length;i++){
Annotation a=as[i];
if(a instanceof Entity_FieldProperty){
Entity_FieldProperty ef=(Entity_FieldProperty)a;
if(ef!=null){
fclass=ef.cls();
fType=ef.FieldType();
}
break;
}
}
if(fType==null||fType!=FieldType.Transient)
list.add(filedName);
}
return list;
}
/*
*得到除開指定名稱的屬性列
*/
public String[] getEntityColumnNames(Class<?> cls,Boolean isRepacePrimaryKeyName,String... exceptCoulums){
List<String> nameList=getEntityColumnNameList(cls);
if(isRepacePrimaryKeyName==null){
isRepacePrimaryKeyName=true;
}
if(exceptCoulums!=null){
for(String s:exceptCoulums){
nameList.remove(s);
}
}
String[] names=new String[nameList.size()];
for(int i=0;i<nameList.size();i++){
names[i]=nameList.get(i);
if(names[i].toLowerCase(Locale.ENGLISH).equals("id")){
names[i]=BaseEntity.primaryKeyName;
}
}
return names;
}
/**失敗返回null
* 傳入代Id值的Entity的值例項
* @param t 返回t
* @return
* @throws Exception
*/
public T get(SQLiteDatabase db,T t) throws Exception{
if(t==null) return null;
Cursor c=null;
try {
c=this.getCursor(db,tableName, null, T.primaryKeyName+"=?", new String[]{t.getId()+""}, null, null, null,null);
if(c.moveToNext())
{ t.initFromCursor(c);
return t;
}else{
return null;
}
} catch (Exception e) {
Log.e(this.getClass().getName()+"T get:",e.toString());
throw e;
}finally{
if(c!=null) c.close();
}
}
/**手動的條件搜尋
* @return
* @throws Exception
*/
public T get(SQLiteDatabase db,Class<T> cls,String[] columns,String selection, String[] selectionArgs, String orderBy) throws Exception{
Cursor c=null;
try {
c=this.getCursor(db,tableName,columns, selection, selectionArgs, null, null, orderBy,"0,1");
if(c.moveToNext())
{ T t=cls.newInstance();
t.initFromCursor(c);
return t;
}else{
return null;
}
} catch (Exception e) {
Log.e(this.getClass().getName()+"T get:",e.toString());
throw e;
}finally{
if(c!=null) c.close();
}
}
/**失敗返回null
* 傳入代Id值的Entity的值例項
* @param t 返回t
* @param exceptCoulums 不需要取出的資料列的名稱
* @return
* @throws Exception
*/
public T get(SQLiteDatabase db,T t,String... exceptCoulums) throws Exception{
if(t==null) return null;
Cursor c=null;
try {
String[] names=getEntityColumnNames(t.getClass(), true,exceptCoulums);
c=this.getCursor(db,tableName,names, T.primaryKeyName+"=?", new String[]{t.getId()+""}, null, null, null,null);
if(c.moveToNext())
{ t.initFromCursor(c);
return t;
}else{
return null;
}
} catch (Exception e) {
Log.e(this.getClass().getName()+"T get:",e.toString());
throw e;
}finally{
if(c!=null) c.close();
}
}
/**
*
* 失敗返回空陣列
* @param db
* @param cls
* @param selection
* @param selectionArgs
* @param orderBy
* @param limit select * from table_name limit N,M //N序號從0開始
* @param exceptCoulums 指定不從資料庫取出的列
* @return
* @throws Exception
*/
public List<T> getList(SQLiteDatabase db,Class<T> cls,String selection, String[] selectionArgs, String orderBy,String limit,String... exceptCoulums) throws Exception{
List<T> ts=new ArrayList<T>();
Cursor c = null;
try {
String[] names=getEntityColumnNames(cls, true, exceptCoulums);
c=this.getCursor(db,tableName,names, selection, selectionArgs, null, null, orderBy,limit);
while(c.moveToNext()){
T t=cls.newInstance();
t.initFromCursor(c);
if(!ts.contains(t))
ts.add(t);
}
} catch (Exception e) {
Log.e("getList:"+cls.getName(),e.toString());
throw e;
}finally{
if(c!=null) c.close();
}
return ts;
}
/**
* 失敗返回空陣列
* @param db
* @param cls
*@param selection
* @param selectionArgs
* @param orderBy
* @param limit select * from table_name limit N,M //N序號從0開始
* @return
* @throws Exception
*/
public List<T> getList(SQLiteDatabase db,Class<T> cls,String selection, String[] selectionArgs, String orderBy,String limit) throws Exception{
List<T> ts=new ArrayList<T>();
Cursor c = null;
try {
c=this.getCursor(db,tableName, null, selection, selectionArgs, null, null, orderBy,limit);
while(c.moveToNext()){
T t=cls.newInstance();
t.initFromCursor(c);
if(!ts.contains(t))
ts.add(t);
}
} catch (Exception e) {
Log.e("getList:"+cls.getName(),e.toString());
throw e;
}finally{
if(c!=null) c.close();
}
return ts;
}
/**
* 獲取資料庫中的所有的記錄
* @param db
* @param cls
* @return
* @throws Exception
*/
public List<T> getList(SQLiteDatabase db,Class<T> cls) throws Exception{
List<T> ts=new ArrayList<T>();
Cursor c = null;
try {
c=this.getCursor(db,tableName, null,null,null, null, null,null,null);
while(c.moveToNext()){
T t=cls.newInstance();
t.initFromCursor(c);
if(!ts.contains(t))
ts.add(t);
}
} catch (Exception e) {
Log.e("getList:"+cls.getName(),e.toString());
throw e;
}finally{
if(c!=null) c.close();
}
return ts;
}
/**
*
* @param t
* @return 插入返回1
* @throws Exception
*/
public void saveOrUpdate(SQLiteDatabase db,T t) throws Exception{
Cursor c = null;
try {
c=this.getCursor(db,tableName, null, T.primaryKeyName+"=?", new String[]{t.getId()+""}, null, null, null,null);
if(c.moveToNext())
{//如果已經存在,則更新,否則insert
t.updateToDataBase(tableName,db);
return;
}
t.saveToDataBase(tableName,db);
return;
} catch (Exception e) {
Log.e("saveOrUpdate:"+t.getClass().getName(),e.toString());
throw e;
}finally{
if(c!=null) c.close();
}
}
/**
*
* @param t
* @return 插入返回1
* @param columnName 如果指定的欄位,有相同的值存在於資料庫,那麼就更新資料庫,否則儲存
* @throws Exception
*/
public void saveOrUpdate(SQLiteDatabase db,T t,String columnName) throws Exception{
Cursor c = null;
try {
c=this.getCursor(db,tableName, null, columnName+"=?", new String[]{t.getClass().getField(columnName).get(t)+""}, null, null, null,null);
if(c.moveToNext())
{//如果已經存在,則更新,否則insert
t.updateToDataBaseByColumn(tableName, db, columnName);
return;
}
t.saveToDataBase(tableName,db);
return;
} catch (Exception e) {
Log.e("saveOrUpdate:"+t.getClass().getName(),e.toString());
throw e;
}finally{
if(c!=null) c.close();
}
}
/**
* 先刪除,後儲存,沒有則不刪除
* @param db
* @param t
* @throws Exception
*/
public void deleteAndSave(SQLiteDatabase db,T t) throws Exception{
try {
this.delete(db, t.getId()+"");
this.save(db, t);
} catch (Exception e) {
Log.e("saveOrUpdate:"+t.getClass().getName(),e.toString());
throw e;
}
}
/**
*
* @param db
* @param list
* @return
* @throws Exception
*/
public void saveOrUpdateList(SQLiteDatabase db,List<T> list) throws Exception{
try{
for(T t:list){
saveOrUpdate(db, t);
}
}catch(Exception e){
throw new Exception("saveOrUpdateList: "+" Fail");
}
}
/**
*
* @param db
* @param list
* @param column 指定列的值相同就更新,否則就儲存
* @throws Exception
*/
public void saveOrUpdateList(SQLiteDatabase db,List<T> list,String column) throws Exception{
try{
for(T t:list){
saveOrUpdate(db, t,column);
}
}catch(Exception e){
throw new Exception("saveOrUpdateList: "+" Fail");
}
}
/**
*刪除後儲存所有
* @param db
* @param list
* @return
* @throws Exception
*/
public void deleteAndSaveList(SQLiteDatabase db,List<T> list) throws Exception{
try{
for(T t:list){
deleteAndSave(db, t);
}
}catch(Exception e){
throw new Exception("saveOrUpdateList: "+" Fail");
}
}
public int update(SQLiteDatabase db,T t) throws Exception{
try {
t.updateToDataBase(tableName,db);
return 2;
} catch (Exception e) {
Log.e("update:"+t.getClass().getName(),e.toString());
throw e;
}
}
/**
*
* @param t
* @param notUpdateColumns 不需要更新的欄位名稱的陣列
* @return
* @throws Exception
*/
public int update(SQLiteDatabase db,T t,String[] notUpdateColumns) throws Exception{
try {
t.updateToDataBase(tableName,db,notUpdateColumns);
return 2;
} catch (Exception e) {
Log.e("update:"+t.getClass().getName(),e.toString());
throw e;
}
}
public int save(SQLiteDatabase db,T t) throws Exception{
try {
t.saveToDataBase(tableName, db);
return 1;
} catch (Exception e) {
Log.e("save:"+t.getClass().getName(),e.toString());
throw e;
}
}
public int delete(SQLiteDatabase db,String id) throws Exception{
if(id.equals("0"))
throw new Exception("刪除的_id號碼不能夠是0,請稍後再試!");
try {
this.delete(db,tableName, id);
return 1;
} catch (Exception e) {
Log.e("delete:"+this.getClass().getName(),e.toString());
throw e;
}
}
public int deleteList(SQLiteDatabase db,String ids) throws Exception{
try {
String whereClause=" "+T.primaryKeyName+" in (?)";
String[] whereArgs=new String[]{ids};
this.delete(db,tableName, whereClause, whereArgs);
return 1;
} catch (Exception e) {
Log.e("deleteList:"+this.getClass().getName(),e.toString());
throw e;
}
}
public int deleteAll(SQLiteDatabase db) throws Exception{
try {
this.delete(db,tableName, null,null);
return 1;
} catch (Exception e) {
Log.e("deleteAll:"+this.getClass().getName(),e.toString());
throw e;
}
}
/**
* 返回搜尋的cursor;
* @param db
* @param sqlString
* @param selectionArgs sql中?佔位符的引數
* @return
*/
public Cursor getCursor(SQLiteDatabase db,String sqlString,String[] selectionArgs){
return db.rawQuery(sqlString,selectionArgs);
}
/**
*
* @param db
* @param sqlString
* @param selectionArgs sql中?佔位符的引數
* @param columns 需要出去的列的名稱,沒有會賦值null;取出的列只支援float/string/blob/string/null這幾種型別;
* *其中二進位制會轉換成為byte[]型別;除開這些型別外,系統會預設用string來取出資料
* @return List<Object[]>
*/
public List<Object[]> getColumns(SQLiteDatabase db,String sqlString,String[] selectionArgs,String...columns){
List<Object[]> list=new ArrayList<Object[]>();
Object[] objs=null;
Cursor cursor=getCursor(db, sqlString, selectionArgs);
while(cursor.moveToNext()){
objs=new Object[columns.length];
try{
for(int i=0;i<columns.length;i++){
String ss=columns[i];
int index=cursor.getColumnIndex(ss);
if(index==-1)
continue;
int columnType =cursor.getType(index);
switch (columnType) {
case Cursor.FIELD_TYPE_NULL:
objs[i]=null;
break;
case Cursor.FIELD_TYPE_INTEGER:
objs[i]=cursor.getInt(index);
break;
case Cursor.FIELD_TYPE_BLOB:
objs[i]=cursor.getBlob(index);
break;
case Cursor.FIELD_TYPE_FLOAT:
objs[i]=cursor.getFloat(index);
break;
case Cursor.FIELD_TYPE_STRING:
objs[i]=cursor.getString(index);
break;
default:
objs[i]=cursor.getString(index);
break;
}
}
list.add(objs);
}catch(ClassCastException e){
e.printStackTrace();
Log.e("BaseAndroidDao:getColumns:",e.toString());
}
}
return list;
}
public Cursor getCursor(SQLiteDatabase db,String table, String[] columns, String selection, String[] selectionArgs, String groupBy, String having, String orderBy,String limit) {
Cursor cursor = db.query(table, columns, selection, selectionArgs, groupBy, having, orderBy,limit);
return cursor;
}
public void execSQL(SQLiteDatabase db,String sql){
db.execSQL(sql);
}
public void execSQL(SQLiteDatabase db,String sql,Object[] objs){
db.execSQL(sql,objs);
}
/**
* 呼叫原生的insert方法,不推薦
* @param tableName
* @param cv
* @return
*/
public long insert(SQLiteDatabase db,String tableName,ContentValues cv)
{
long row = db.insert(tableName, null, cv);
return row;
}
/**
* 呼叫自己寫的方法,insert into person(name,phone) values (?,?)
* @param p
*/
public void save(SQLiteDatabase db,String sql,Object[] objs)
{
db.execSQL(sql, objs);
}
public void update(SQLiteDatabase db,String sql,Object[] objs){
db.execSQL(sql, objs);
}
//刪除操作
public void delete(SQLiteDatabase db,String tableName,String id)
{
String where =BaseEntity.primaryKeyName + "=?";
String[] whereValue ={id};
db.delete(tableName, where, whereValue);
}
//刪除操作
public void delete(SQLiteDatabase db,String table, String whereClause, String[] whereArgs)
{
db.delete(table, whereClause, whereArgs);
}
//修改操作
public void update(SQLiteDatabase db,String tableName,int id, ContentValues cv)
{
String where = BaseEntity.primaryKeyName+ "=?";
String[] whereValue = { Integer.toString(id) };
db.update(tableName, cv, where, whereValue);
}
//修改操作
public void update(SQLiteDatabase db,String tableName,ContentValues cv, String where,String[] whereValue)
{
db.update(tableName, cv, where, whereValue);
}
public String getTableName() {
return tableName;
}
public void setTableName(String tableName) {
this.tableName = tableName;
}
}3:使用示例:
public class LoginTypeService {
private String tableName="loginType";
private BaseAndroidDao<LoginType> baseDao;
public LoginTypeService(){
baseDao=new BaseAndroidDao<LoginType>(tableName);
}
public LoginType getLoginType(){
LoginType lt=new LoginType();
lt.setId(1L);
SQLiteDatabase db = null;
try {
db=baseDao.openDataBase();
lt=baseDao.get(db, lt);
return lt;
} catch (Exception e) {
return null;
}finally{
baseDao.closeDataBase();
}
}
public boolean saveOrUpdate(LoginType loginType){
if(loginType==null||loginType.getId()==null)
return false;
SQLiteDatabase db = null;
try {
db=baseDao.openDataBase();
db.beginTransaction();
baseDao.saveOrUpdate(db, loginType);
db.setTransactionSuccessful();
return true;
} catch (Exception e) {
return false;
}finally{
if(db!=null)
db.endTransaction();
baseDao.closeDataBase();
}
}
}注意:Service層,就是是控制層來負責事務的管理;