mybatis generator自動生成程式碼時將blob屬性變成String型別,當出現亂碼時的處理方法
1.blob屬性變成String型別,需要在配置檔案中的table元素中增加columnOverride元素,詳情如下例子:
<table tableName="paas_conf_metadata">
<generatedKey column="ID" sqlStatement="MySql" identity="true"/>
//column指blob屬性修飾的欄位名,javaType的值是生成程式碼後轉換的型別,需要些類全名,這裡是String型別,jdbcType是jdbc型別。
<columnOverride column="DEFAULT_VALUES" javaType="java.lang.String" jdbcType="BLOB" typeHandler="com.cmf.diccer.handler.tool.StringBlobTypeHandler"/>
</table>
2.當轉換過程中出現亂碼時,需要增加typeHandler屬性,如上面所示。
StringBlobTypeHandler的程式碼如下:
import java.io.ByteArrayInputStream;
import java.io.UnsupportedEncodingException;
import java.sql.Blob;
import java.sql.CallableStatement;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import org.apache.ibatis.type.BaseTypeHandler;
import org.apache.ibatis.type.JdbcType;
public class StringBlobTypeHandler extends BaseTypeHandler<String> {
// ###指定字符集
private static final String DEFAULT_CHARSET = "utf-8";
public void setNonNullParameter(PreparedStatement ps, int i, String parameter, JdbcType jdbcType)
throws SQLException {
ByteArrayInputStream bis;
byte[] bytes = null;
try {
bytes = parameter.getBytes(DEFAULT_CHARSET);
// ###把String轉化成byte流
bis = new ByteArrayInputStream(bytes);
} catch (UnsupportedEncodingException e) {
throw new RuntimeException("Blob Encoding Error!");
}
ps.setBinaryStream(i, bis, bytes.length);
}
@Override
public String getNullableResult(ResultSet rs, String columnName) throws SQLException {
Blob blob = (Blob) rs.getBlob(columnName);
byte[] returnValue = null;
if (null != blob) {
returnValue = blob.getBytes(1, (int) blob.length());
}
try {
if (returnValue == null) {
return null;
}
// ###把byte轉化成string
return new String(returnValue, DEFAULT_CHARSET);
} catch (UnsupportedEncodingException e) {
throw new RuntimeException("Blob Encoding Error!");
}
}
public String getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
Blob blob = (Blob) cs.getBlob(columnIndex);
byte[] returnValue = null;
if (null != blob) {
returnValue = blob.getBytes(1, (int) blob.length());
}
try {
return new String(returnValue, DEFAULT_CHARSET);
} catch (UnsupportedEncodingException e) {
throw new RuntimeException("Blob Encoding Error!");
}
}
@Override
public String getNullableResult(ResultSet rs, int columnIndex) throws SQLException {
// TODO Auto-generated method stub
return null;
}
}
注:以上程式碼是借鑑別人的,但有做適當修改。