java利用反射打印出类的结构

1 输入一个类名：java.lang.String将打印出String类定义的结构，例如：

public final class java.lang.String

{

  public java.lang.String([B,int,int);

  public java.lang.String([B,java.nio.charset.Charset);

  public java.lang.String([B,java.lang.String);

  public java.lang.String([B,int,int,java.nio.charset.Charset);

  public java.lang.String([B,int,int,java.lang.String);

  java.lang.String([C,boolean);

  public java.lang.String(java.lang.StringBuilder);

  public java.lang.String(java.lang.StringBuffer);

  public java.lang.String([B);

  public java.lang.String([I,int,int);

  public java.lang.String();

  public java.lang.String([C);

  public java.lang.String(java.lang.String);

  public java.lang.String([C,int,int);

  public java.lang.String([B,int);

  public java.lang.String([B,int,int,int);

  public boolean equals(java.lang.Object);

  public java.lang.String toString();

  public int hashCode();

  public int compareTo(java.lang.String);

  public volatile int compareTo(java.lang.Object);

  public int indexOf(java.lang.String,int);

  public int indexOf(java.lang.String);

  public int indexOf(int,int);

  public int indexOf(int);

  static int indexOf([C,int,int,[C,int,int,int);

  static int indexOf([C,int,int,java.lang.String,int);

  public static java.lang.String valueOf(int);

  public static java.lang.String valueOf(long);

  public static java.lang.String valueOf(float);

  public static java.lang.String valueOf(boolean);

  public static java.lang.String valueOf([C);

  public static java.lang.String valueOf([C,int,int);

  public static java.lang.String valueOf(java.lang.Object);

  public static java.lang.String valueOf(char);

  public static java.lang.String valueOf(double);

  public char charAt(int);

  private static void checkBounds([B,int,int);

  public int codePointAt(int);

  public int codePointBefore(int);

  public int codePointCount(int,int);

  public int compareToIgnoreCase(java.lang.String);

  public java.lang.String concat(java.lang.String);

  public boolean contains(java.lang.CharSequence);

  public boolean contentEquals(java.lang.CharSequence);

  public boolean contentEquals(java.lang.StringBuffer);

  public static java.lang.String copyValueOf([C);

  public static java.lang.String copyValueOf([C,int,int);

  public boolean endsWith(java.lang.String);

  public boolean equalsIgnoreCase(java.lang.String);

  public static transient java.lang.String format(java.util.Locale,java.lang.String,[Ljava.lang.Object;);

  public static transient java.lang.String format(java.lang.String,[Ljava.lang.Object;);

  public void getBytes(int,int,[B,int);

  public [B getBytes(java.nio.charset.Charset);

  public [B getBytes(java.lang.String);

  public [B getBytes();

  public void getChars(int,int,[C,int);

void getChars([C,int);

  private int indexOfSupplementary(int,int);

  public native java.lang.String intern();

  public boolean isEmpty();

  public static transient java.lang.String join(java.lang.CharSequence,[Ljava.lang.CharSequence;);

  public static java.lang.String join(java.lang.CharSequence,java.lang.Iterable);

  public int lastIndexOf(int);

  public int lastIndexOf(java.lang.String);

  static int lastIndexOf([C,int,int,java.lang.String,int);

  public int lastIndexOf(java.lang.String,int);

  public int lastIndexOf(int,int);

  static int lastIndexOf([C,int,int,[C,int,int,int);

  private int lastIndexOfSupplementary(int,int);

  public int length();

  public boolean matches(java.lang.String);

  private boolean nonSyncContentEquals(java.lang.AbstractStringBuilder);

  public int offsetByCodePoints(int,int);

  public boolean regionMatches(int,java.lang.String,int,int);

  public boolean regionMatches(boolean,int,java.lang.String,int,int);

  public java.lang.String replace(char,char);

  public java.lang.String replace(java.lang.CharSequence,java.lang.CharSequence);

  public java.lang.String replaceAll(java.lang.String,java.lang.String);

  public java.lang.String replaceFirst(java.lang.String,java.lang.String);

  public [Ljava.lang.String; split(java.lang.String);

  public [Ljava.lang.String; split(java.lang.String,int);

  public boolean startsWith(java.lang.String,int);

  public boolean startsWith(java.lang.String);

  public java.lang.CharSequence subSequence(int,int);

  public java.lang.String substring(int);

  public java.lang.String substring(int,int);

  public [C toCharArray();

  public java.lang.String toLowerCase(java.util.Locale);

  public java.lang.String toLowerCase();

  public java.lang.String toUpperCase();

  public java.lang.String toUpperCase(java.util.Locale);

  public java.lang.String trim();

  private final [C value;

  private int hash;

  private static final long serialVersionUID;

  private static final [Ljava.io.ObjectStreamField; serialPersistentFields;

  public static final java.util.Comparator CASE_INSENSITIVE_ORDER;

}

主程序如下：

    public static void main(String[] args) throws ClassNotFoundException

    {

String name;

        if (args.length>) {

            name=args[];

        }

        else {

            Scanner in=new Scanner(System.in);

            System.out.println("enter class name(e.g java.util.Date)");

            name=in.next();

        }

        try {

            Class c1=Class.forName(name);

            Class superClass=c1.getSuperclass();

            //获取类的修饰符

            String modifiers=Modifier.toString(c1.getModifiers());

            if (modifiers.length()>) {

                System.out.print(modifiers+" ");

            }

            System.out.print("class "+c1.getName());

            if (superClass!=null&&superClass!=Object.class) {

                System.out.print(" extends "+superClass.getName());

            }

            //\n表示换行

            System.out.print("\n{\n");

            //打印构造器

            printConstractors(c1);

            System.out.println();

            //打印类的方法

            printMethods(c1);

            System.out.println();

            //打印域

            printFields(c1);

            System.out.println("}");

        } catch (Exception e) {

            // TODO: handle exception

        }

        }

private static void printFields(Class c1) {

        // TODO Auto-generated method stub

        Field[] fields= c1.getDeclaredFields();

        for (Field field : fields) {

            Class type= field.getType();

            String name=field.getName();

            System.out.print("  ");

            String modifiers=Modifier.toString(field.getModifiers());

            if (modifiers.length()>) {

                System.out.print(modifiers+" ");

            }

            System.out.println(type.getName()+" "+name+";");

        }

    }

    private static void printMethods(Class c1) {

        // TODO Auto-generated method stub

        //获取当前类的所有方法

        Method[] methods= c1.getDeclaredMethods();

        for (Method m : methods) {

            Class returnType= m.getReturnType();

            String methodName=m.getName();

            String modifiers=Modifier.toString(m.getModifiers());

            if (modifiers.length()>) {

                System.out.print("  "+modifiers+" ");

            }

            System.out.print(returnType.getName()+" "+methodName+"(");

            //打印方法参数

            Class[] paramTypes= m.getParameterTypes();

            for (int i = ; i < paramTypes.length; i++) {

                if (i>) {

                    System.out.print(",");

                }

                System.out.print(paramTypes[i].getName());

            }

            System.out.println(");");

        }

    }

    private static void printConstractors(Class c1) {

        // TODO Auto-generated method stub

        //得到当前类的所有构造器，包括受保护的和私有的，不包含超类的

        Constructor[] constructors= c1.getDeclaredConstructors();

        for (Constructor constructor : constructors) {

            System.out.print("  ");

            String name=constructor.getName();

            String modifiers=Modifier.toString(constructor.getModifiers());

            if (modifiers.length()>) {

                System.out.print(modifiers+" ");

            }

            System.out.print(name+"(");

            //打印构造器的参数

            Class[] paramsTypes= constructor.getParameterTypes();

            for (int i = ; i < paramsTypes.length; i++) {

                if (i>) {

                    System.out.print(",");

                }

                System.out.print(paramsTypes[i].getName());

            }

            System.out.println(");");

        }

    }

巴特西

java利用反射打印出类的结构

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