反编译那些事儿（二）—枚举的反编译

说明：下面的反编译结果使用“http://download.csdn.net/detail/wangshuxuncom/6841823”处的反编译工具反编译的。

一、不含有抽象的方法

源码如下：

import java.util.Arrays;import java.util.List;public enum Weather {	Sunny(1, "晴天"), Rainy(2, "雨天"), Cloudy(3, "多云");	private int value;	private String label;	private Weather(int value, String label) {		this.value = value;		this.label = label;	}	public int getValue() {		retu value;	}	public String getLabel() {		retu label;	}	public static Weather parse(int value) {		Weather result = Weather.Sunny;		switch (value) {		case 1:			result = Weather.Sunny;			break;		case 2:			result = Weather.Rainy;			break;		case 3:			result = Weather.Cloudy;			break;		}		retu result;	}	public static List<Weather> getEnumValues() {		retu Arrays.asList(values());	}	public static void main(String[] args) {		System.out.println(Weather.Sunny.getValue() + ":" + Weather.Sunny.getLabel());		Weather weather = Weather.Cloudy;		System.out.println(weather.getValue() + ":" + weather.getLabel());		List<Weather> list = getEnumValues();		for (Weather sw : list) {			System.out.println(sw.value + "--" + sw.label);		}	}}

反编译生成的class文件后的代码如下：

/*import java.io.PrintStream;*/import java.util.*;public final class Weather extends Enum{		private Weather(/*String s, int i,*/ int value, String label){		/*super(s, i);*/		this.value = value;		this.label = label;	}		public int getValue(){		retu value;	}		public String getLabel(){		retu label;	}		public static Weather parse(int value){		Weather result = Sunny;		switch(value){			case 1: /*// '\001'*/				result = Sunny;				break;			case 2: /*// '\002'*/				result = Rainy;				break;			case 3: /*// '\003'*/				result = Cloudy;				break;		}		retu result;	}		public static List getEnumValues(){		retu Arrays.asList(values());	}		public static void main(String args[]){		System.out.println((new StringBuilder(String.valueOf(Sunny.getValue()))).append(":").append(Sunny.getLabel()).toString());		Weather weather = Cloudy;		System.out.println((new StringBuilder(String.valueOf(weather.getValue()))).append(":").append(weather.getLabel()).toString());		List list = getEnumValues();		Weather sw;		for(Iterator iterator = list.iterator(); iterator.hasNext(); System.out.println((new StringBuilder(String.valueOf(sw.value))).append("--").append(sw.label).toString()))			sw = (Weather)iterator.next();	}		/*public static Weather[] values(){		Weather aweather[];		int i;		Weather aweather1[];		System.arraycopy(aweather = ENUM$VALUES, 0, aweather1 = new Weather[i = aweather.length], 0, i);		retu aweather1;	}*/		/*public static Weather valueOf(String s){		retu (Weather)Enum.valueOf(Weather, s);	}*/		/*public static final Weather*/ Sunny;	/*public static final Weather*/ Rainy;	/*public static final Weather*/ Cloudy;	private int value;	private String label;	/*private static final Weather ENUM$VALUES[];*/	static {		Sunny = new Weather(/*"Sunny", 0,*/ 1, "\u6674\u5929");		Rainy = new Weather(/*"Rainy", 1,*/ 2, "\u96E8\u5929");		Cloudy = new Weather(/*"Cloudy", 2,*/ 3, "\u591A\u4E91");		/*ENUM$VALUES = (new Weather[] {			Sunny, Rainy, Cloudy		});*/	}}

注意：所有/**/中间的东西都是多余的（/**/是人为添加的）

如何将反编译代码还原：

①、去掉被/**/掉的代码，去掉后代码如下：

import java.util.*;public final class Weather extends Enum{private Weather(int value, String label){	this.value = value;	this.label = label;}public int getValue(){	retu value;}public String getLabel(){	retu label;}public static Weather parse(int value){ Weather result = Sunny; switch(value){ 	case 1: 		result = Sunny; 			break; 	case 2: 		result = Rainy; 		break; 	case 3: 		result = Cloudy; 		break;}retu result;}public static List getEnumValues(){	retu Arrays.asList(values());}public static void main(String args[]){	System.out.println((new StringBuilder(String.valueOf(Sunny.getValue()))).append(":").append(Sunny.getLabel()).toString());Weather weather = Cloudy;System.out.println((new StringBuilder(String.valueOf(weather.getValue()))).append(":").append(weather.getLabel()).toString());List list = getEnumValues();Weather sw;for(Iterator iterator = list.iterator(); iterator.hasNext(); System.out.println((new StringBuilder(String.valueOf(sw.value))).append("--").append(sw.label).toString()))sw = (Weather)iterator.next();	}Sunny;Rainy;Cloudy;private int value;private String label;static {	Sunny = new Weather(1, "\u6674\u5929");	Rainy = new Weather(2, "\u96E8\u5929");	Cloudy = new Weather(3, "\u591A\u4E91");}}

②、在上一步的基础上对照非反编译中的java源码可以还原大概，呵呵呵，可能你会说“狗屁，我要是知道源码了，还反编译干什么”，呵呵呵，别急，如果你能把上面的这个弄明白了，你就会反编译没有源码参考的枚举类了。

③、呵呵呵，本来到此就可以了事了，可是还是禁不住提几个地方：注意反编译前java文件和反编译后生成的java文件在引类的区别；注意反编译class文件后的泛型没有了；从反编译的结果中可以得出这样的结论：实际上枚举类型就是以Java类来实现的，没有什么新的特点，只不过java编译器帮我们做了语法的解析和编译。

二、含有抽象的方法

源码如下：

import java.util.Arrays;import java.util.List;public enum Weather {		Sunny(1, "晴天") {		@Override		public String test() {			retu "今天阳光明媚！！！\n";		}	},	Rainy(2, "雨天") {		@Override		public String test() {			retu "出门别忘带把雨伞哦！！！\n";		}	},	Cloudy(3, "多云") {		@Override		public String test() {			retu "别出去登高望远了，你看不远的，呵呵呵！！！\n";		}	};	private int value;	private String label;	private Weather(int value, String label) {		this.value = value;		this.label = label;	}	public int getValue() {		retu value;	}	public String getLabel() {		retu label;	}	public abstract String test();	public static Weather parse(int value) {		Weather result = Weather.Sunny;		switch (value) {		case 1:			result = Weather.Sunny;			break;		case 2:			result = Weather.Rainy;			break;		case 3:			result = Weather.Cloudy;			break;		}		retu result;	}	public static List<Weather> getEnumValues() {		retu Arrays.asList(values());	}	public static void main(String[] args) {		System.out.println(Weather.Sunny.getValue() + ":" + Weather.Sunny.getLabel());		Weather weather = Weather.Cloudy;		System.out.println(weather.getValue() + ":" + weather.getLabel() + "\n\n");		List<Weather> list = getEnumValues();		for (Weather sw : list) {			System.out.println(sw.value + "--" + sw.label + "--" + sw.test());		}	}}

反编译生成的class文件后的代码如下：

import java.io.PrintStream;import java.util.*;public abstract class Weather extends Enum {	private Weather(String s, int i, int value, String label) {		super(s, i);		this.value = value;		this.label = label;	}	public int getValue() {		retu value;	}	public String getLabel() {		retu label;	}	public abstract String test();	public static Weather parse(int value) {		Weather result = Sunny;		switch (value) {		case 1: // '\001'			result = Sunny;			break;		case 2: // '\002'			result = Rainy;			break;		case 3: // '\003'			result = Cloudy;			break;		}		retu result;	}	public static List getEnumValues() {		retu Arrays.asList(values());	}	public static void main(String args[]) {		System.out.println((new StringBuilder(String.valueOf(Sunny.getValue()))).append(":").append(Sunny.getLabel()).toString());		Weather weather = Cloudy;		System.out.println((new StringBuilder(String.valueOf(weather.getValue()))).append(":").append(weather.getLabel()).append("\n\n").toString());		List list = getEnumValues();		Weather sw;		for (Iterator iterator = list.iterator(); iterator.hasNext(); System.out.println((new StringBuilder(String.valueOf(sw.value))).append("--").append(sw.label).append("--").append(sw.test()).toString()))			sw = (Weather) iterator.next();	}	public static Weather[] values() {		Weather aweather[];		int i;		Weather aweather1[];		System.arraycopy(aweather = ENUM$VALUES, 0, aweather1 = new Weather[i = aweather.length], 0, i);		retu aweather1;	}	public static Weather valueOf(String s) {		retu (Weather) Enum.valueOf(Weather, s);	}	Weather(String s, int i, int j, String s1, Weather weather) {		this(s, i, j, s1);	}	public static final Weather Sunny;	public static final Weather Rainy;	public static final Weather Cloudy;	private int value;	private String label;	private static final Weather ENUM$VALUES[];	static {		Sunny = new Weather("Sunny", 0, 1, "\u6674\u5929") {			public String test() {				retu "\u4ECA\u5929\u9633\u5149\u660E\u5A9A\uFF01\uFF01\uFF01\n";			}		};		Rainy = new Weather("Rainy", 1, 2, "\u96E8\u5929") {			public String test() {				retu "\u51FA\u95E8\u522B\u5FD8\u5E26\u628A\u96E8\u4F1E\u54E6\uFF01\uFF01\uFF01\n";			}		};		Cloudy = new Weather("Cloudy", 2, 3, "\u591A\u4E91") {			public String test() {				retu "\u522B\u51FA\u53BB\u767B\u9AD8\u671B\u8FDC\u4E86\uFF0C\u4F60\u770B\u4E0D\u8FDC\u7684\uFF0C\u5475\u5475\u5475\uFF01\uFF01\uFF01\n";			}		};		ENUM$VALUES = (new Weather[] { Sunny, Rainy, Cloudy });	}}

总结：对比源代码和编译代码，找出他们的区别并不难，做到这一点就可以反编译含有抽象方法的枚举class文件，呵呵呵呵，将“不含抽象方法”的class反编译文件和“含有抽象方法”的class反编译文件，你应该还有一个很大的收获，呵呵呵，看着：

“不含抽象方法”的class反编译文件：public final class Weather extends Enum

“含有抽象方法”的class反编译文件：public abstractclass Weather extends Enum