關於反射裡的內部類和外部類
最近寫適配，遇到了一點小問題，
1.通過反射得到某個例項，可是這個例項是內部類，想要得到並通過invoke方法執行外部類的方法，需要得到外部類的例項，通過網上查閱，每一個內部類都有一個this$0的變數是指向外部類的引用，通過getdeclearedField得到這個引用，然後setaccessible(true)得到訪問許可權例項化外部類就得到了，此時這個內部類的例項對應的外部類的例項了。
可是我這裡的內部類是static的，上面的this$0是有限制的，靜態內部類和靜態方法裡面的內部類是沒有this$0這個引用的，因為靜態內部類，是面向類的而不是物件，能夠獨自的應用本身，而脫離外部類，和外部類沒有這個引用關係。
2. 還有一個方法是要invoke的方法在內部類，得到的例項是外部類，想得到對應的內部類的例項，並沒有這層關係。所以這個方法不可行
在這裡記錄下通過外部類得到內部類的方法：
clazz.getDeclaredClasses();
通過內部類得到外部類的方法：
Clazz.getDeclaringClass();
得到類的建構函式
clazz.getConstructors()
得到類的所有建構函式
clazz.getDeclaredConstructor();
注意：建構函式通過getmethod是得不到的！只能通過getdeclaredconstructor/getconstructors得到
最後解決的辦法，在前輩的幫助下，發現setheader方法，最終是走的內部類的request裡面的add方法這樣就不需要關聯內部類和外部類了。下面是asynchttpclient一個類的程式碼：
package com.ning.http.client;
import com.ning.http.client.cookie.Cookie;
import com.ning.http.client.multipart.Part;
import com.ning.http.client.uri.Uri;
import com.ning.http.util.AsyncHttpProviderUtils;
import com.ning.http.util.MiscUtils;
import com.ning.http.util.UriEncoder;
import java.io.File;
import java.io.InputStream;
import java.net.InetAddress;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public abstract class RequestBuilderBase<T extends RequestBuilderBase<T>>
{
private static final Logger logger = LoggerFactory.getLogger(RequestBuilderBase.class);
private static final Uri DEFAULT_REQUEST_URL = Uri.create("http://localhost");
private final Class<T> derived;
protected final RequestImpl request;
protected UriEncoder uriEncoder;
protected List<Param> rbQueryParams;
protected SignatureCalculator signatureCalculator;
private static final class RequestImpl
implements Request
{
private String method;
private Uri uri;
private InetAddress address;
private InetAddress localAddress;
private FluentCaseInsensitiveStringsMap headers = new FluentCaseInsensitiveStringsMap();
private ArrayList<Cookie> cookies;
private byte[] byteData;
private List<byte[]> compositeByteData;
private String stringData;
private InputStream streamData;
private BodyGenerator bodyGenerator;
private List<Param> formParams;
private List<Part> parts;
private String virtualHost;
private long length = -1L;
public ProxyServer proxyServer;
private Realm realm;
private File file;
private Boolean followRedirects;
private int requestTimeout;
private long rangeOffset;
public String charset;
private ConnectionPoolPartitioning connectionPoolPartitioning = ConnectionPoolPartitioning.PerHostConnectionPoolPartitioning.INSTANCE;
private NameResolver nameResolver = NameResolver.JdkNameResolver.INSTANCE;
private List<Param> queryParams;
public RequestImpl() {}
public RequestImpl(Request prototype)
{
if (prototype != null)
{
this.method = prototype.getMethod();
this.uri = prototype.getUri();
this.address = prototype.getInetAddress();
this.localAddress = prototype.getLocalAddress();
this.headers = new FluentCaseInsensitiveStringsMap(prototype.getHeaders());
this.cookies = new ArrayList(prototype.getCookies());
this.byteData = prototype.getByteData();
this.compositeByteData = prototype.getCompositeByteData();
this.stringData = prototype.getStringData();
this.streamData = prototype.getStreamData();
this.bodyGenerator = prototype.getBodyGenerator();
this.formParams = (prototype.getFormParams() == null ? null : new ArrayList(prototype.getFormParams()));
this.parts = (prototype.getParts() == null ? null : new ArrayList(prototype.getParts()));
this.virtualHost = prototype.getVirtualHost();
this.length = prototype.getContentLength();
this.proxyServer = prototype.getProxyServer();
this.realm = prototype.getRealm();
this.file = prototype.getFile();
this.followRedirects = prototype.getFollowRedirect();
this.requestTimeout = prototype.getRequestTimeout();
this.rangeOffset = prototype.getRangeOffset();
this.charset = prototype.getBodyEncoding();
this.connectionPoolPartitioning = prototype.getConnectionPoolPartitioning();
this.nameResolver = prototype.getNameResolver();
}
}
public String getMethod()
{
return this.method;
}
public InetAddress getInetAddress()
{
return this.address;
}
public InetAddress getLocalAddress()
{
return this.localAddress;
}
public Uri getUri()
{
return this.uri;
}
public String getUrl()
{
return this.uri.toUrl();
}
public FluentCaseInsensitiveStringsMap getHeaders()
{
return this.headers;
}
public Collection<Cookie> getCookies()
{
return this.cookies != null ? Collections.unmodifiableCollection(this.cookies) : Collections.emptyList();
}
public byte[] getByteData()
{
return this.byteData;
}
public List<byte[]> getCompositeByteData()
{
return this.compositeByteData;
}
public String getStringData()
{
return this.stringData;
}
public InputStream getStreamData()
{
return this.streamData;
}
public BodyGenerator getBodyGenerator()
{
return this.bodyGenerator;
}
public long getContentLength()
{
return this.length;
}
public List<Param> getFormParams()
{
return this.formParams != null ? this.formParams : Collections.emptyList();
}
public List<Part> getParts()
{
return this.parts != null ? this.parts : Collections.emptyList();
}
public String getVirtualHost()
{
return this.virtualHost;
}
public ProxyServer getProxyServer()
{
return this.proxyServer;
}
public Realm getRealm()
{
return this.realm;
}
public File getFile()
{
return this.file;
}
public Boolean getFollowRedirect()
{
return this.followRedirects;
}
public int getRequestTimeout()
{
return this.requestTimeout;
}
public long getRangeOffset()
{
return this.rangeOffset;
}
public String getBodyEncoding()
{
return this.charset;
}
public ConnectionPoolPartitioning getConnectionPoolPartitioning()
{
return this.connectionPoolPartitioning;
}
public NameResolver getNameResolver()
{
return this.nameResolver;
}
public List<Param> getQueryParams()
{
if (this.queryParams == null) {
if (MiscUtils.isNonEmpty(this.uri.getQuery()))
{
this.queryParams = new ArrayList(1);
for (String queryStringParam : this.uri.getQuery().split("&"))
{
int pos = queryStringParam.indexOf('=');
if (pos <= 0) {
this.queryParams.add(new Param(queryStringParam, null));
} else {
this.queryParams.add(new Param(queryStringParam.substring(0, pos), queryStringParam.substring(pos + 1)));
}
}
}
else
{
this.queryParams = Collections.emptyList();
}
}
return this.queryParams;
}
public String toString()
{
StringBuilder sb = new StringBuilder(getUrl());
sb.append("\t");
sb.append(this.method);
sb.append("\theaders:");
if (MiscUtils.isNonEmpty(this.headers)) {
for (String name : this.headers.keySet())
{
sb.append("\t");
sb.append(name);
sb.append(":");
sb.append(this.headers.getJoinedValue(name, ", "));
}
}
if (MiscUtils.isNonEmpty(this.formParams))
{
sb.append("\tformParams:");
for (Param param : this.formParams)
{
sb.append("\t");
sb.append(param.getName());
sb.append(":");
sb.append(param.getValue());
}
}
return sb.toString();
}
}
protected RequestBuilderBase(Class<T> derived, String method, boolean disableUrlEncoding)
{
this(derived, method, UriEncoder.uriEncoder(disableUrlEncoding));
}
protected RequestBuilderBase(Class<T> derived, String method, UriEncoder uriEncoder)
{
this.derived = derived;
this.request = new RequestImpl();
this.request.method = method;
this.uriEncoder = uriEncoder;
}
protected RequestBuilderBase(Class<T> derived, Request prototype)
{
this(derived, prototype, UriEncoder.FIXING);
}
protected RequestBuilderBase(Class<T> derived, Request prototype, UriEncoder uriEncoder)
{
this.derived = derived;
this.request = new RequestImpl(prototype);
this.uriEncoder = uriEncoder;
}
public T setUrl(String url)
{
return setUri(Uri.create(url));
}
public T setUri(Uri uri)
{
this.request.uri = uri;
return (RequestBuilderBase)this.derived.cast(this);
}
public T setInetAddress(InetAddress address)
{
this.request.address = address;
return (RequestBuilderBase)this.derived.cast(this);
}
public T setLocalInetAddress(InetAddress address)
{
this.request.localAddress = address;
return (RequestBuilderBase)this.derived.cast(this);
}
public T setVirtualHost(String virtualHost)
{
this.request.virtualHost = virtualHost;
return (RequestBuilderBase)this.derived.cast(this);
}
public T setHeader(String name, String value)
{
this.request.headers.replaceWith(name, new String[] { value });
return (RequestBuilderBase)this.derived.cast(this);
}
public T addHeader(String name, String value)
{
if (value == null)
{
logger.warn("Value was null, set to \"\"");
value = "";
}
this.request.headers.add(name, value);
return (RequestBuilderBase)this.derived.cast(this);
}
public T setHeaders(FluentCaseInsensitiveStringsMap headers)
{
this.request.headers = (headers == null ? new FluentCaseInsensitiveStringsMap() : new FluentCaseInsensitiveStringsMap(headers));
return (RequestBuilderBase)this.derived.cast(this);
}
public T setHeaders(Map<String, Collection<String>> headers)
{
this.request.headers = (headers == null ? new FluentCaseInsensitiveStringsMap() : new FluentCaseInsensitiveStringsMap(headers));
return (RequestBuilderBase)this.derived.cast(this);
}
public T setContentLength(int length)
{
this.request.length = length;
return (RequestBuilderBase)this.derived.cast(this);
}
private void lazyInitCookies()
{
if (this.request.cookies == null) {
this.request.cookies = new ArrayList(3);
}
}
public T setCookies(Collection<Cookie> cookies)
{
this.request.cookies = new ArrayList(cookies);
return (RequestBuilderBase)this.derived.cast(this);
}
public T addCookie(Cookie cookie)
{
lazyInitCookies();
this.request.cookies.add(cookie);
return (RequestBuilderBase)this.derived.cast(this);
}
public T addOrReplaceCookie(Cookie cookie)
{
String cookieKey = cookie.getName();
boolean replace = false;
int index = 0;
lazyInitCookies();
for (Cookie c : this.request.cookies)
{
if (c.getName().equals(cookieKey))
{
replace = true;
break;
}
index++;
}
if (replace) {
this.request.cookies.set(index, cookie);
} else {
this.request.cookies.add(cookie);
}
return (RequestBuilderBase)this.derived.cast(this);
}
public void resetCookies()
{
if (this.request.cookies != null) {
this.request.cookies.clear();
}
}
public void resetQuery()
{
this.rbQueryParams = null;
this.request.uri = this.request.uri.withNewQuery(null);
}
public void resetFormParams()
{
this.request.formParams = null;
}
public void resetNonMultipartData()
{
this.request.byteData = null;
this.request.compositeByteData = null;
this.request.stringData = null;
this.request.streamData = null;
this.request.bodyGenerator = null;
this.request.length = -1L;
}
public void resetMultipartData()
{
this.request.parts = null;
}
public T setBody(File file)
{
this.request.file = file;
return (RequestBuilderBase)this.derived.cast(this);
}
public T setBody(byte[] data)
{
resetFormParams();
resetNonMultipartData();
resetMultipartData();
this.request.byteData = data;
return (RequestBuilderBase)this.derived.cast(this);
}
public T setBody(List<byte[]> data)
{
resetFormParams();
resetNonMultipartData();
resetMultipartData();
this.request.compositeByteData = data;
return (RequestBuilderBase)this.derived.cast(this);
}
public T setBody(String data)
{
resetFormParams();
resetNonMultipartData();
resetMultipartData();
this.request.stringData = data;
return (RequestBuilderBase)this.derived.cast(this);
}
public T setBody(InputStream stream)
{
resetFormParams();
resetNonMultipartData();
resetMultipartData();
this.request.streamData = stream;
return (RequestBuilderBase)this.derived.cast(this);
}
public T setBody(BodyGenerator bodyGenerator)
{
this.request.bodyGenerator = bodyGenerator;
return (RequestBuilderBase)this.derived.cast(this);
}
public T addQueryParam(String name, String value)
{
if (this.rbQueryParams == null) {
this.rbQueryParams = new ArrayList(1);
}
this.rbQueryParams.add(new Param(name, value));
return (RequestBuilderBase)this.derived.cast(this);
}
public T addQueryParams(List<Param> params)
{
if (this.rbQueryParams == null) {
this.rbQueryParams = params;
} else {
this.rbQueryParams.addAll(params);
}
return (RequestBuilderBase)this.derived.cast(this);
}
private List<Param> map2ParamList(Map<String, List<String>> map)
{
if (map == null) {
return null;
}
List<Param> params = new ArrayList(map.size());
for (Map.Entry<String, List<String>> entries : map.entrySet())
{
name = (String)entries.getKey();
for (String value : (List)entries.getValue()) {
params.add(new Param(name, value));
}
}
String name;
return params;
}
public T setQueryParams(Map<String, List<String>> map)
{
return setQueryParams(map2ParamList(map));
}
public T setQueryParams(List<Param> params)
{
if (MiscUtils.isNonEmpty(this.request.uri.getQuery())) {
this.request.uri = this.request.uri.withNewQuery(null);
}
this.rbQueryParams = params;
return (RequestBuilderBase)this.derived.cast(this);
}
public T addFormParam(String name, String value)
{
resetNonMultipartData();
resetMultipartData();
if (this.request.formParams == null) {
this.request.formParams = new ArrayList(1);
}
this.request.formParams.add(new Param(name, value));
return (RequestBuilderBase)this.derived.cast(this);
}
public T setFormParams(Map<String, List<String>> map)
{
return setFormParams(map2ParamList(map));
}
public T setFormParams(List<Param> params)
{
resetNonMultipartData();
resetMultipartData();
this.request.formParams = params;
return (RequestBuilderBase)this.derived.cast(this);
}
public T addBodyPart(Part part)
{
resetFormParams();
resetNonMultipartData();
if (this.request.parts == null) {
this.request.parts = new ArrayList();
}
this.request.parts.add(part);
return (RequestBuilderBase)this.derived.cast(this);
}
public T setProxyServer(ProxyServer proxyServer)
{
this.request.proxyServer = proxyServer;
return (RequestBuilderBase)this.derived.cast(this);
}
public T setRealm(Realm realm)
{
this.request.realm = realm;
return (RequestBuilderBase)this.derived.cast(this);
}
public T setFollowRedirects(boolean followRedirects)
{
this.request.followRedirects = Boolean.valueOf(followRedirects);
return (RequestBuilderBase)this.derived.cast(this);
}
public T setRequestTimeout(int requestTimeout)
{
this.request.requestTimeout = requestTimeout;
return (RequestBuilderBase)this.derived.cast(this);
}
public T setRangeOffset(long rangeOffset)
{
this.request.rangeOffset = rangeOffset;
return (RequestBuilderBase)this.derived.cast(this);
}
public T setMethod(String method)
{
this.request.method = method;
return (RequestBuilderBase)this.derived.cast(this);
}
public T setBodyEncoding(String charset)
{
this.request.charset = charset;
return (RequestBuilderBase)this.derived.cast(this);
}
public T setConnectionPoolKeyStrategy(ConnectionPoolPartitioning connectionPoolKeyStrategy)
{
this.request.connectionPoolPartitioning = connectionPoolKeyStrategy;
return (RequestBuilderBase)this.derived.cast(this);
}
public T setNameResolver(NameResolver nameResolver)
{
this.request.nameResolver = nameResolver;
return (RequestBuilderBase)this.derived.cast(this);
}
public T setSignatureCalculator(SignatureCalculator signatureCalculator)
{
this.signatureCalculator = signatureCalculator;
return (RequestBuilderBase)this.derived.cast(this);
}
private void executeSignatureCalculator()
{
if (this.signatureCalculator != null)
{
RequestBuilder rb = (RequestBuilder)new RequestBuilder(this.request).setSignatureCalculator(null);
rb.rbQueryParams = this.rbQueryParams;
Request unsignedRequest = rb.build();
this.signatureCalculator.calculateAndAddSignature(unsignedRequest, this);
}
}
private void computeRequestCharset()
{
if (this.request.charset == null) {
try
{
String contentType = this.request.headers.getFirstValue("Content-Type");
if (contentType != null)
{
String charset = AsyncHttpProviderUtils.parseCharset(contentType);
if (charset != null) {
this.request.charset = charset;
}
}
}
catch (Throwable localThrowable) {}
}
}
private void computeRequestLength()
{
if ((this.request.length < 0L) && (this.request.streamData == null))
{
String contentLength = this.request.headers.getFirstValue("Content-Length");
if (contentLength != null) {
try
{
this.request.length = Long.parseLong(contentLength);
}
catch (NumberFormatException localNumberFormatException) {}
}
}
}
private void validateSupportedScheme(Uri uri)
{
String scheme = uri.getScheme();
if ((scheme == null) || ((!scheme.equalsIgnoreCase("http")) && (!scheme.equalsIgnoreCase("https")) && (!scheme.equalsIgnoreCase("ws")) &&
(!scheme.equalsIgnoreCase("wss")))) {
throw new IllegalArgumentException("The URI scheme, of the URI " + uri + ", must be equal (ignoring case) to 'http', 'https', 'ws', or 'wss'");
}
}
private void computeFinalUri()
{
if (this.request.uri == null)
{
logger.debug("setUrl hasn't been invoked. Using {}", DEFAULT_REQUEST_URL);
this.request.uri = DEFAULT_REQUEST_URL;
}
else
{
validateSupportedScheme(this.request.uri);
}
this.request.uri = this.uriEncoder.encode(this.request.uri, this.rbQueryParams);
}
public Request build()
{
executeSignatureCalculator();
computeFinalUri();
computeRequestCharset();
computeRequestLength();
return this.request;
}
}