Java内容重新整理删除过期的东西

Java/JavaDemo/codedemo/java/lang/reflect/ClassAnalyze.java

@@ -0,0 +1,143 @@
+package cn.aofeng.demo.java.lang.reflect;
+
+import java.lang.annotation.Annotation;
+import java.lang.reflect.AnnotatedElement;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Field;
+import java.lang.reflect.Member;
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+
+/**
+ * 通过反射获取类的构造方法、字段、方法和注解等信息。
+ * 
+ * @author <a href="mailto:aofengblog@163.com">聂勇</a>
+ */
+public class ClassAnalyze {
+
+    final static String PREFIX = "==========";
+    final static String SUFFIX = PREFIX;
+    
+    private static void parseClass(Class<?> claz) {
+        // 注解
+        parseAnnotation(claz);
+        
+        // 类
+        StringBuilder buffer = new StringBuilder(32)
+            .append( Modifier.toString(claz.getModifiers()) )
+            .append(' ')
+            .append(claz.getName());
+        log(buffer.toString());
+    }
+    
+    private static void parseConstructor(Constructor<?> c) {
+        // 注解
+        parseAnnotation(c);
+        
+        // 构造方法
+        StringBuilder buffer = new StringBuilder(32)
+            .append( parseMember(c) )
+            .append('(');
+        
+        // 参数
+        Class<?>[] params = c.getParameterTypes();
+        for (int index = 0; index < params.length; index++) {
+            buffer.append(params[index].getName());
+            if (index!=params.length-1) {
+                buffer.append(", ");
+            }
+        }
+        buffer.append(')');
+        
+        log(buffer.toString());
+    }
+    
+    private static void parseMethod(Method method) {
+        // 注解
+        parseAnnotation(method);
+        
+        // 方法
+        StringBuilder buffer = new StringBuilder(32)
+            .append( parseMember(method) )
+            .append('(');
+        
+        // 参数
+        Class<?>[] params = method.getParameterTypes();
+        for (int index = 0; index < params.length; index++) {
+            buffer.append(params[index].getName());
+            if (index!=params.length-1) {
+                buffer.append(", ");
+            }
+        }
+        buffer.append(')');
+        
+        log(buffer.toString());
+    }
+    
+    private static void parseField(Field field) {
+        // 注解
+        parseAnnotation(field);
+        
+        // 字段
+        StringBuilder buffer = parseMember(field);
+        log(buffer.toString());
+    }
+    
+    /**
+     * 解析方法、字段或构造方法的信息。
+     * @param member 方法、字段或构造方法
+     * @return 修饰符和名称组成的字符串。
+     */
+    private static StringBuilder parseMember(Member member) {
+        StringBuilder buffer = new StringBuilder()
+            .append(Modifier.toString(member.getModifiers()))
+            .append(' ')
+            .append(member.getName());
+        return buffer;
+    }
+    
+    /**
+     * 解析注解信息。
+     */
+    private static void parseAnnotation(AnnotatedElement ae) {
+        Annotation[] ans = ae.getDeclaredAnnotations();
+        for (Annotation annotation : ans) {
+            log(annotation.toString());
+        }
+    }
+    
+    public static void log(String msg, Object... param) {
+        System.out.println( String.format(msg, param) );
+    }
+    
+    public static void main(String[] args) throws ClassNotFoundException {
+        if (args.length != 1) {
+            log("无效的输入参数！");
+            log("示例：");
+            log("java cn.aofeng.demo.java.lang.reflect.ClassAnalyze java.util.HashMap");
+        }
+        Class<?> claz = Class.forName(args[0]);
+        
+        log("%s类%s", PREFIX, SUFFIX);
+        parseClass(claz);
+        
+        log("%s构造方法%s", PREFIX, SUFFIX);
+        Constructor<?>[] cs = claz.getDeclaredConstructors();
+        for (Constructor<?> constructor : cs) {
+            parseConstructor(constructor);
+        }
+        
+        log("%s字段%s", PREFIX, SUFFIX);
+        Field[] fields = claz.getDeclaredFields();
+        for (Field field : fields) {
+            parseField(field);
+        }
+        
+        log("%s方法%s", PREFIX, SUFFIX);
+        Method[] methods = claz.getDeclaredMethods();
+        for (Method method : methods) {
+            parseMethod(method);
+        }
+    }
+
+}

Java/JavaDemo/codedemo/java/lang/reflect/CreateInstance.java

@@ -0,0 +1,36 @@
+package cn.aofeng.demo.java.lang.reflect;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+
+import cn.aofeng.demo.util.LogUtil;
+
+/**
+ * 通过反射使用构造方法创建对象实例。
+ * 
+ * @author <a href="mailto:aofengblog@163.com">聂勇</a>
+ */
+public class CreateInstance {
+
+    public static void main(String[] args) throws InstantiationException, IllegalAccessException, 
+            NoSuchMethodException, SecurityException,
+            IllegalArgumentException, InvocationTargetException {
+        Class<Man> claz = Man.class;
+        
+        // 调用默认的public构造方法
+        Man man = claz.newInstance();
+        LogUtil.log(man.toString());
+        
+        // 调用带参数的protected构造方法
+        Constructor<Man> manC = claz.getDeclaredConstructor(String.class);
+        man = manC.newInstance("aofeng");
+        LogUtil.log(man.toString());
+        
+        // 调用带参数的private构造方法
+        manC = claz.getDeclaredConstructor(String.class, int.class);
+        manC.setAccessible(true);
+        man = manC.newInstance("NieYong", 32);
+        LogUtil.log(man.toString());
+    }
+
+}

Java/JavaDemo/codedemo/java/lang/reflect/InvokeField.java

@@ -0,0 +1,37 @@
+package cn.aofeng.demo.java.lang.reflect;
+
+import java.lang.reflect.Field;
+
+import static cn.aofeng.demo.util.LogUtil.log;
+
+/**
+ * 通过反射设置字段。
+ * 
+ * @author <a href="mailto:aofengblog@163.com">聂勇</a>
+ */
+public class InvokeField {
+
+    public static void main(String[] args) throws NoSuchFieldException,
+            SecurityException, IllegalArgumentException, IllegalAccessException {
+        Man man = new Man();
+        Class<?> claz = man.getClass();
+        
+        log("==========设置public字段的值==========");
+        log("height的值:%d", man.height);
+        Field field = claz.getField("height");
+        field.setInt(man, 175);
+        log("height的值:%d", man.height);
+        
+        log("==========设置private字段的值==========");
+        log("power的值:%d", man.getPower());
+        field = claz.getDeclaredField("power");
+        field.setAccessible(true);
+        field.setInt(man, 100);
+        log("power的值:%d", man.getPower());
+        
+        log("==========获取private字段的值==========");
+        int power = field.getInt(man);
+        log("power的值:%d", power);
+    }
+
+}

Java/JavaDemo/codedemo/java/lang/reflect/InvokeMethod.java

@@ -0,0 +1,84 @@
+package cn.aofeng.demo.java.lang.reflect;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+
+import static cn.aofeng.demo.util.LogUtil.log;
+
+/**
+ * 通过反射调用方法。
+ * 
+ * @author <a href="mailto:aofengblog@163.com">聂勇</a>
+ */
+public class InvokeMethod {
+
+    /**
+     * 调用父类的方法。
+     * 
+     * @param claz
+     *            类
+     * @param man
+     *            类对应的实例
+     */
+    private static void invokeParentMethod(Class<Man> claz, Man man)
+            throws NoSuchMethodException, IllegalAccessException,
+            InvocationTargetException {
+        // 调用父类的public方法
+        Method method = claz.getMethod("setName", String.class);
+        method.invoke(man, "NieYong");
+        log(man.toString());
+
+        method = claz.getMethod("getName");
+        Object result = method.invoke(man);
+        log("name:%s", result);
+
+        // 调用父类的private方法
+        method = claz.getSuperclass().getDeclaredMethod("reset");
+        method.setAccessible(true);
+        result = method.invoke(man);
+        log(man.toString());
+    }
+
+    /**
+     * 调用自身的方法。
+     * 
+     * @param claz
+     *            类
+     * @param man
+     *            类对应的实例
+     */
+    private static void invokeSelfMethod(Class<Man> claz, Man man)
+            throws NoSuchMethodException, IllegalAccessException,
+            InvocationTargetException {
+        man.setName("XiaoMing");
+        // 调用自身的private方法
+        Method method = claz.getDeclaredMethod("setPower", int.class);
+        method.setAccessible(true);
+        method.invoke(man, 99);
+        log("power:%d", man.getPower());
+
+        // 调用自身的public方法
+        log("%s is marry:%s", man.getName(), (man.isMarry() ? "Yes" : "No"));
+        method = claz.getDeclaredMethod("setMarry", boolean.class);
+        method.invoke(man, true);
+        log("%s is marry:%s", man.getName(), (man.isMarry() ? "Yes" : "No"));
+
+        // 调用静态方法，可将实例设置为null，因为静态方法属于类
+        Man a = new Man("张三");
+        Man b = new Man("李四");
+        method = claz.getMethod("fight", Man.class, Man.class);
+        method.invoke(null, a, b); //
+    }
+
+    public static void main(String[] args) throws NoSuchMethodException,
+            SecurityException, IllegalAccessException,
+            IllegalArgumentException, InvocationTargetException,
+            InstantiationException {
+        Class<Man> claz = Man.class;
+        Man man = claz.newInstance();
+
+        invokeParentMethod(claz, man);
+        invokeSelfMethod(claz, man);
+    }
+
+}

Java/JavaDemo/codedemo/java/lang/reflect/Man.java

@@ -0,0 +1,63 @@
+package cn.aofeng.demo.java.lang.reflect;
+
+import cn.aofeng.demo.json.gson.Person;
+import cn.aofeng.demo.util.LogUtil;
+
+/**
+ * 男人。
+ * 
+ * @author <a href="mailto:aofengblog@163.com">聂勇</a>
+ */
+public class Man extends Person {
+
+    private boolean marry;
+    
+    private int power;
+    
+    public int height;
+
+    public Man() {
+        super();
+        LogUtil.log("%s的默认构造方法被调用", Man.class.getName());
+    }
+    
+    protected Man(String name) {
+        super(name, 0);
+        LogUtil.log("%s带name参数的构造方法被调用", Man.class.getName());
+    }
+    
+    @SuppressWarnings("unused")
+    private Man(String name, int age) {
+        super(name, age);
+        LogUtil.log("%s带name和age参数的构造方法被调用", Man.class.getName());
+    }
+    
+    public static void fight(Man a, Man b) {
+        String win = "unkown";
+        if (a.power > b.power) {
+            win = a.getName();
+        } else if (b.power > a.power) {
+            win = a.getName();
+        }
+        
+        LogUtil.log("%s vs %s, fight result:%s", a.getName(), b.getName(), win);
+    }
+    
+    public boolean isMarry() {
+        return marry;
+    }
+
+    public void setMarry(boolean marry) {
+        this.marry = marry;
+    }
+
+    public int getPower() {
+        return power;
+    }
+
+    @SuppressWarnings("unused")
+    private void setPower(int power) {
+        this.power = power;
+    }
+
+}