1.功能：简化的异常处理
2.代码：
package com.example.google.guava.demo.clazz;
import com.example.google.guava.demo.exception.InvalidInputException;
import com.google.common.base.Throwables;
import java.io.IOException;
import java.util.List;
//import org.eclipse.jdt.core.compiler.InvalidInputException;
/**
* <p>
* <code>ThrowablesTest</code>
* </p>
* Description:
*
* @author Mcchu
* @date 2017/10/19 9:57
*/
public class ThrowablesTest {
public static void main(String[] args) {
System.out.println("================1.InvalidInputException==================");
try {
showThrowableSqrt();
}catch (InvalidInputException e){
// Guava的异常链处理方法：获得根异常
Throwable able = Throwables.getRootCause(e);
// Guava的异常链处理方法：获得异常的列表
List throwableList = Throwables.getCausalChain(e);
System.out.println( able );
System.out.println( throwableList );
}
System.out.println("================2.ArrayIndexOutOfBoundsException==================");
try {
showThrowableArray();
}catch (Exception e){
// Guava的异常链处理方法：获得异常堆栈的字符串
String stackTrace = Throwables.getStackTraceAsString(e);
System.out.println( stackTrace );
}
System.out.println("================3.IOException==================");
try {
showThrowableIO();
}catch (Exception e){
// 获取堆栈异常信息
String stackTrace = Throwables.getStackTraceAsString(e);
System.out.println( stackTrace );
}
}
/**
* 测试一
*/
private static void showThrowableSqrt() throws InvalidInputException{
try {
sqrt(-3.0);
} catch (Throwable e) {
// 检测异常类型并抛出：
/*
* @deprecated Use {@link #throwIfInstanceOf}, which has the same behavior but rejects {@code
* null}. This method is scheduled to be removed in July 2018.
*/
Throwables.propagateIfInstanceOf(e, InvalidInputException.class); // 此方法将于2018.7移除
//Throwables.throwIfInstanceOf(e, InvalidInputException.class);
/*
* @deprecated Use {@code throw e} or {@code throw new RuntimeException(e)} directly, or use a
* combination of {@link #throwIfUnchecked} and {@code throw new RuntimeException(e)}. For
* background on the deprecation, read <a href="https://goo.gl/Ivn2kc">Why we deprecated
* {@code Throwables.propagate}</a>. This method is scheduled to be removed in July 2018.
*/
Throwables.propagate(e); // 此方法将于2018.7移除
//Throwables.throwIfUnchecked(e);
}
}
/**
* 测试二
*/
private static void showThrowableArray(){
try {
int[] data = {1,2,3};
getValue(data, 4);
} catch (Throwable e) {
Throwables.propagateIfInstanceOf(e, IndexOutOfBoundsException.class);
Throwables.propagate(e);
}
}
/**
* 测试三
*/
private static void showThrowableIO(){
try {
dummyIO();
} catch (Throwable e) {
Throwables.propagateIfInstanceOf(e, IndexOutOfBoundsException.class);
Throwables.propagate(e);
}
}
/**
* 自定义异常测试：InvalidInputException
* 注意：此处的InvalidInputException不是org.eclipse.jdt.core.compiler.InvalidInputException
* @param input 传入参数
* @return 平方根
* @throws InvalidInputException 自定义异常
*/
private static double sqrt(double input) throws InvalidInputException{
if(input < 0) throw new InvalidInputException("求平方根出了点问题，你再试试！");
return Math.sqrt(input);
}
/**
* 数组越界异常测试：IndexOutOfBoundsException
* @param list 整型数组
* @param index 数组长度
* @return 数组指定元素
* @throws IndexOutOfBoundsException 数组越界
*/
private static double getValue(int[] list, int index) throws IndexOutOfBoundsException {
return list[index];
}
/**
* IO异常测试：IOException
* @throws IOException io异常
*/
private static void dummyIO() throws IOException {
throw new IOException();
}
}
3.输出结果：
com.example.google.guava.demo.exception.InvalidInputException: 求平方根出了点问题，你再试试！ [com.example.google.guava.demo.exception.InvalidInputException: 求平方根出了点问题，你再试试！] ================2.ArrayIndexOutOfBoundsException================== java.lang.ArrayIndexOutOfBoundsException: 4 at com.example.google.guava.demo.clazz.ThrowablesTest.getValue(ThrowablesTest.java:132) at com.example.google.guava.demo.clazz.ThrowablesTest.showThrowableArray(ThrowablesTest.java:93) at com.example.google.guava.demo.clazz.ThrowablesTest.main(ThrowablesTest.java:42) ================3.IOException================== java.lang.RuntimeException: java.io.IOException at com.google.common.base.Throwables.propagate(Throwables.java:241) at com.example.google.guava.demo.clazz.ThrowablesTest.showThrowableIO(ThrowablesTest.java:108) at com.example.google.guava.demo.clazz.ThrowablesTest.main(ThrowablesTest.java:52) Caused by: java.io.IOException at com.example.google.guava.demo.clazz.ThrowablesTest.dummyIO(ThrowablesTest.java:140) at com.example.google.guava.demo.clazz.ThrowablesTest.showThrowableIO(ThrowablesTest.java:105) ... 1 more
4.方法说明：
传递异常的常用方法：
1.RuntimeException propagate(Throwable)：把throwable包装成RuntimeException，用该方法保证异常传递，抛出一个RuntimeException异常 2.void propagateIfInstanceOf(Throwable, Class<X extends Exception>) throws X：当且仅当它是一个X的实例时，传递throwable 3.void propagateIfPossible(Throwable)：当且仅当它是一个RuntimeException和Error时，传递throwable 4.void propagateIfPossible(Throwable, Class<X extends Throwable>) throws X：当且仅当它是一个RuntimeException和Error时，或者是一个X的实例时，传递throwable。
附录：
1.InvalidInputException.java
package com.example.google.guava.demo.exception;
/**
* <p>
* <code>InvalidInputException</code>
* </p>
* Description:
*
* @author Mcchu
* @date 2017/10/19 10:19
*/
public class InvalidInputException extends Exception{
public InvalidInputException( String message ){
super( message );
}
}
2.参考：
http://www.yiibai.com/guava/guava_throwables_class.html
http://www.cnblogs.com/peida/p/Guava_Throwables.html
http://outofmemory.cn/java/guava/base/Throwables