施用反射获取类的字段,方法信息

使用反射获取类的字段,方法信息
  今天在查看javax.mail包中相关类的信息时,想了解一下每一个类的属性,行为概要信息,以及它们之间的关联关系,本来eUML2可以看的,无奈试用过期了,又不想花银子,等找到好的Eclipse插件再说吧.

package com.pa.reflection;import java.io.*;import java.lang.reflect.*;@SuppressWarnings("rawtypes")public class ClassReflection {private static final String BLANK = " ";private static final String LEFT_BRACKET = "(";private static final String RIGHT_BRACKET = ")";private static final String THROWS = "throws";private static final String SEPARATE = ";";private static final String NEW_LINE = "\r\n";private static final String COMMA = ",";private static final String ARG = "arg";public static void getClassInfo(Class<?> clazz, Writer writer) {try {//获取构造函数信息StringBuffer constructorsResult = getConstructors(clazz);//获取字段信息StringBuffer fieldsResult = getFields(clazz);//获取方法信息StringBuffer methodsResult = getMethods(clazz);//最终结果StringBuffer finalResult = new StringBuffer();finalResult.append(constructorsResult).append(NEW_LINE);finalResult.append(fieldsResult).append(NEW_LINE);finalResult.append(methodsResult).append(NEW_LINE);//输出结果writer.write(finalResult.toString());} catch (Exception e) {e.printStackTrace();} finally {if (writer != null)try {writer.close();} catch (Exception e) {e.printStackTrace();}}}private static StringBuffer getMethods(Class<?> clazz) {Method[] methods = clazz.getDeclaredMethods();beforeGetClassMethods(clazz,methods);StringBuffer methodsResult = new StringBuffer();if (methods != null && methods.length > 0) {for (Method method : methods) {methodsResult.append(addSuffixBlank(Modifier.toString(method.getModifiers())));methodsResult.append(addSuffixBlank(method.getReturnType().getCanonicalName()));methodsResult.append(method.getName());Class[] parameterTypes = method.getParameterTypes();getParameters(methodsResult, parameterTypes);Class[] exceptionTypes = method.getExceptionTypes();getExceptions(methodsResult, exceptionTypes);methodsResult.append(SEPARATE);methodsResult.append(NEW_LINE);}}afterGetClassMethods(clazz,methods);return methodsResult;}private static void afterGetClassMethods(Class<?> clazz,Method[] methods) {}private static void beforeGetClassMethods(Class<?> clazz,Method[] methods) {System.out.println("get "+clazz.getCanonicalName()+" methods,totoal size: "+methods.length);}/** * 获取方法异常信息 * @param methodsResult * @param exceptionTypes */private static void getExceptions(StringBuffer methodsResult,Class[] exceptionTypes) {if (exceptionTypes != null && exceptionTypes.length > 0) {methodsResult.append(addSuffixBlank(THROWS));for (int j = 0; j < exceptionTypes.length; j++) {Class exceptionType = exceptionTypes[j];methodsResult.append(exceptionType.getCanonicalName());if (j != exceptionTypes.length - 1) {methodsResult.append(COMMA);} }}}/** * 获取方法参数信息 * @param methodsResult * @param parameterTypes */private static void getParameters(StringBuffer methodsResult,Class[] parameterTypes) {methodsResult.append(LEFT_BRACKET);if (parameterTypes != null && parameterTypes.length > 0) {for (int i = 0; i < parameterTypes.length; i++) {Class parameterType = parameterTypes[i];methodsResult.append(addSuffixBlank(parameterType.getCanonicalName())).append(ARG + (i + 1));if (i != parameterTypes.length - 1) {methodsResult.append(COMMA);} }}methodsResult.append(RIGHT_BRACKET);}private static StringBuffer getFields(Class<?> clazz) {Field[] fields = clazz.getDeclaredFields();beforeGetClassFields(clazz,fields);StringBuffer fieldsResult = new StringBuffer();if (fields != null && fields.length > 0) {for (Field field : fields) {fieldsResult.append(addSuffixBlank(Modifier.toString((field.getModifiers()))));fieldsResult.append(addSuffixBlank(field.getType().getCanonicalName()));fieldsResult.append(field.getName());fieldsResult.append(SEPARATE);fieldsResult.append(NEW_LINE);}}afterGetClassFields(clazz,fields);return fieldsResult;}private static void afterGetClassFields(Class<?> clazz,Field[] fields) {}private static void beforeGetClassFields(Class<?> clazz,Field[] fields) {System.out.println("get "+clazz.getCanonicalName()+" fieds,totoal size: "+fields.length);}private static StringBuffer getConstructors(Class<?> clazz) {Constructor[] constructors = clazz.getDeclaredConstructors();beforeGetClassContructors(clazz,constructors);StringBuffer constructorsResult = new StringBuffer();if (constructors != null && constructors.length > 0) {for (Constructor constructor : constructors) {constructorsResult.append(addSuffixBlank(Modifier.toString(constructor.getModifiers())));constructorsResult.append(addSuffixBlank(constructor.getName()));Class[] parameterTypes = constructor.getParameterTypes();getParameters(constructorsResult, parameterTypes);Class[] exceptionTypes = constructor.getExceptionTypes();getExceptions(constructorsResult, exceptionTypes);constructorsResult.append(SEPARATE);constructorsResult.append(NEW_LINE);}}afterGetClassContructors(clazz,constructors);return constructorsResult;}private static void afterGetClassContructors(Class<?> clazz,Constructor[] constructors) {}private static void beforeGetClassContructors(Class<?> clazz,Constructor[] constructors) {System.out.println("get "+clazz.getCanonicalName()+" constructors,totoal size: "+constructors.length);}public static String addPrefix(String str, String prefix) {return prefix + str;}public static String addSuffix(String str, String suffix) {return str + suffix;}public static String addPrefixAndSuffix(String str, String prefix,String suffix) {return prefix + str + suffix;}public static String addSuffixBlank(String str) {return addSuffix(str, BLANK);}public static void main(String[] args) throws IOException {Writer writer = new PrintWriter(System.out);System.out.println("请输入你要反射的类(输入'exit'则退出):");BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));String destClass = null;    while(true){    destClass = reader.readLine();    if(destClass.equalsIgnoreCase("exit")){    break;    }try {Class clazz = Class.forName(destClass);getClassInfo(clazz, writer);} catch (ClassNotFoundException e) {e.printStackTrace();}    }}}

get javax.mail.Part constructors,totoal size: 0get javax.mail.Part fieds,totoal size: 2get javax.mail.Part methods,totoal size: 25public static final java.lang.String ATTACHMENT;public static final java.lang.String INLINE;public abstract int getSize()throws javax.mail.MessagingException;public abstract java.lang.String getFileName()throws javax.mail.MessagingException;public abstract java.lang.Object getContent()throws java.io.IOException,javax.mail.MessagingException;public abstract java.io.InputStream getInputStream()throws java.io.IOException,javax.mail.MessagingException;public abstract java.lang.String getContentType()throws javax.mail.MessagingException;public abstract void writeTo(java.io.OutputStream arg1)throws java.io.IOException,javax.mail.MessagingException;public abstract void setText(java.lang.String arg1)throws javax.mail.MessagingException;public abstract int getLineCount()throws javax.mail.MessagingException;public abstract boolean isMimeType(java.lang.String arg1)throws javax.mail.MessagingException;public abstract java.lang.String getDisposition()throws javax.mail.MessagingException;public abstract void setDisposition(java.lang.String arg1)throws javax.mail.MessagingException;public abstract java.lang.String getDescription()throws javax.mail.MessagingException;public abstract void setDescription(java.lang.String arg1)throws javax.mail.MessagingException;public abstract void setFileName(java.lang.String arg1)throws javax.mail.MessagingException;public abstract javax.activation.DataHandler getDataHandler()throws javax.mail.MessagingException;public abstract void setDataHandler(javax.activation.DataHandler arg1)throws javax.mail.MessagingException;public abstract void setContent(javax.mail.Multipart arg1)throws javax.mail.MessagingException;public abstract void setContent(java.lang.Object arg1,java.lang.String arg2)throws javax.mail.MessagingException;public abstract java.lang.String[] getHeader(java.lang.String arg1)throws javax.mail.MessagingException;public abstract void setHeader(java.lang.String arg1,java.lang.String arg2)throws javax.mail.MessagingException;public abstract void addHeader(java.lang.String arg1,java.lang.String arg2)throws javax.mail.MessagingException;public abstract void removeHeader(java.lang.String arg1)throws javax.mail.MessagingException;public abstract java.util.Enumeration getAllHeaders()throws javax.mail.MessagingException;public abstract java.util.Enumeration getMatchingHeaders(java.lang.String[] arg1)throws javax.mail.MessagingException;public abstract java.util.Enumeration getNonMatchingHeaders(java.lang.String[] arg1)throws javax.mail.MessagingException;