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com.github.phantomthief.util.NameServiceUtils Maven / Gradle / Ivy
package com.github.phantomthief.util;
import static com.google.common.base.Preconditions.checkState;
import static com.google.common.base.Throwables.throwIfUnchecked;
import static com.google.common.reflect.Reflection.newProxy;
import static org.apache.commons.lang3.reflect.FieldUtils.readDeclaredStaticField;
import static org.apache.commons.lang3.reflect.FieldUtils.writeStaticField;
import java.lang.reflect.InvocationTargetException;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.List;
import javax.annotation.Nonnull;
import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.reflect.MethodUtils;
import com.github.phantomthief.tuple.Tuple;
import com.github.phantomthief.tuple.TwoTuple;
/**
* @author w.vela
* Created on 2019-12-25.
*/
public class NameServiceUtils {
private static R doInvoke(Object object, String method, T it) throws UnknownHostException {
try {
//noinspection unchecked
return (R) MethodUtils.invokeMethod(object, true, method, it);
} catch (NoSuchMethodException | IllegalAccessException e) {
throw new AssertionError(e);
} catch (InvocationTargetException e) {
Throwable cause = e.getCause();
if (cause instanceof UnknownHostException) {
throw (UnknownHostException) cause;
}
throwIfUnchecked(cause);
throw new AssertionError(cause);
}
}
private static TwoTuple> unwrapList(Object object) {
if (object instanceof List) {
List list = (List) object;
checkState(!list.isEmpty(), "empty nameService in jdk8");
checkState(list.size() == 1, "multiple nameServices in jdk8");
return Tuple.tuple(list.get(0), list);
} else {
throw new IllegalStateException("unknown jdk impl.");
}
}
private static T adapterFromUnifiedNameService(UnifiedNameService unifiedNameService,
Class nameServiceInterface) {
return newProxy(nameServiceInterface, (proxy, method, args) -> {
String name = method.getName();
if (name.equals("lookupAllHostAddr")) {
return unifiedNameService.lookupAllHostAddr((String) args[0]);
} else if (name.equals("getHostByAddr")) {
return unifiedNameService.getHostByAddr((byte[]) args[0]);
} else {
return method.invoke(unifiedNameService, args);
}
});
}
private static void setNameServiceJdk8(UnifiedNameService unifiedNameService, Object originalNameService0) {
TwoTuple> tuple = unwrapList(originalNameService0);
Object originalNameService = tuple.getFirst();
List list = tuple.getSecond();
Class nameServiceInterface = originalNameService.getClass().getInterfaces()[0];
Object wrappedNameService = adapterFromUnifiedNameService(unifiedNameService, nameServiceInterface);
list.set(0, wrappedNameService);
}
private static void setNameServiceJdk9(UnifiedNameService unifiedNameService, Object originalNameService)
throws IllegalAccessException {
Class nameServiceInterface = originalNameService.getClass().getInterfaces()[0];
Object wrappedNameService = adapterFromUnifiedNameService(unifiedNameService, nameServiceInterface);
writeStaticField(InetAddress.class, "nameService", wrappedNameService, true);
}
/**
* @throws IllegalStateException 如果jdk8模式下已经使用SPI方式注入过多个实现时，或者开启JPMS时，权限不够
*/
public static UnifiedNameService getCurrentNameService() {
try {
// jdk9
Object nameService9 = readDeclaredStaticField(InetAddress.class, "nameService", true);
if (nameService9 != null) {
checkJdk9(nameService9);
return new UnifiedNameServiceAdapter(nameService9);
}
} catch (IllegalArgumentException | IllegalAccessException e) {
// ignore
}
try { // jdk8
Object nameServices8 = readDeclaredStaticField(InetAddress.class, "nameServices", true);
if (nameServices8 != null) {
TwoTuple> nameService8 = unwrapList(nameServices8);
checkJdk8(nameService8.getFirst());
return new UnifiedNameServiceAdapter(nameService8.getFirst());
}
throw new IllegalStateException("illegal jdk impl.");
} catch (IllegalAccessException e) {
throw new IllegalStateException(e);
}
}
private static void checkJdk8(Object nameService8) {
try {
String result = doInvoke(nameService8, "getHostByAddr", InetAddress.getLocalHost().getAddress());
} catch (UnknownHostException e) {
// ignore
} catch (Throwable e) {
throw new IllegalStateException(e);
}
}
private static void checkJdk9(Object nameService9) {
checkState(StringUtils.equals("java.net.InetAddress$PlatformNameService", nameService9.getClass().getName()),
"unsupported jdk9+ impl.");
try {
String result = doInvoke(nameService9, "getHostByAddr", InetAddress.getLocalHost().getAddress());
} catch (UnknownHostException e) {
// ignore
} catch (Throwable e) {
throw new IllegalStateException(e);
}
}
/**
* @throws IllegalStateException 如果jdk8模式下已经使用SPI方式注入过多个实现时，或者开启JPMS时，权限不够
*/
public static void setNameService(UnifiedNameService unifiedNameService) {
try {
// jdk9
Object nameService = readDeclaredStaticField(InetAddress.class, "nameService", true);
if (nameService != null) {
setNameServiceJdk9(unifiedNameService, nameService);
return;
}
} catch (IllegalArgumentException | IllegalAccessException e) {
// ignore
}
try {
// jdk8
Object nameService = readDeclaredStaticField(InetAddress.class, "nameServices", true);
if (nameService != null) {
setNameServiceJdk8(unifiedNameService, nameService);
}
} catch (IllegalAccessException e) {
throw new IllegalStateException(e);
}
}
private static class UnifiedNameServiceAdapter implements UnifiedNameService {
private final Object object;
UnifiedNameServiceAdapter(@Nonnull Object obj) {
this.object = obj;
}
@Override
public InetAddress[] lookupAllHostAddr(String host) throws UnknownHostException {
return doInvoke(object, "lookupAllHostAddr", host);
}
@Override
public String getHostByAddr(byte[] addr) throws UnknownHostException {
return doInvoke(object, "getHostByAddr", addr);
}
}
}
