Java常用类库ApacheCommons工具类说明及使用实例详解

//1、 克隆对象 
  // 新创建一个普通Java Bean，用来作为被克隆的对象 
   
    public class Person { 
    private String name = ""; 
    private String email = ""; 
   
    private int age; 
    //省略 set,get方法 
    } 
   
  // 再创建一个Test类，其中在main方法中代码如下： 
    import java.lang.reflect.InvocationTargetException; 
    import java.util.HashMap; 
    import java.util.Map; 
    import org.apache.commons.beanutils.BeanUtils; 
    import org.apache.commons.beanutils.ConvertUtils; 
    public class Test { 
   
    /** 
   
    * @param args 
   
    */ 
    public static void main(String[] args) { 
    Person person = new Person(); 
    person.setName("tom"); 
    person.setAge(21); 
    try { 
        //克隆 
      Person person2 = (Person)BeanUtils.cloneBean(person); 
      System.out.println(person2.getName()+">>"+person2.getAge()); 
    } catch (IllegalAccessException e) { 
      e.printStackTrace(); 
    } catch (InstantiationException e) { 
      e.printStackTrace(); 
    } catch (InvocationTargetException e) { 
      e.printStackTrace(); 
    } catch (NoSuchMethodException e) { 
      e.printStackTrace(); 
   
    } 
   
    } 
   
    } 
   
  // 原理也是通过Java的反射机制来做的。 
  // 2、 将一个Map对象转化为一个Bean 
  // 这个Map对象的key必须与Bean的属性相对应。 
    Map map = new HashMap(); 
    map.put("name","tom"); 
    map.put("email","tom@"); 
    map.put("age","21"); 
    //将map转化为一个Person对象 
    Person person = new Person(); 
    BeanUtils.populate(person,map); 
  // 通过上面的一行代码，此时person的属性就已经具有了上面所赋的值了。 
  // 将一个Bean转化为一个Map对象了，如下： 
    Map map = BeanUtils.describe(person)

//1、 将JavaBean转为XML内容 
    // 新创建一个Person类 
    public class Person{ 
      private String name; 
      private int age; 
      /** Need to allow bean to be created via reflection */ 
      public PersonBean() { 
      } 
      public PersonBean(String name, int age) { 
        this.name = name; 
        this.age = age; 
      } 
      //省略set, get方法 
      public String toString() { 
        return "PersonBean[name='" + name + "',age='" + age + "']"; 
      } 
    } 
     
    //再创建一个WriteApp类： 
    import java.io.StringWriter; 
    import org.apache.commons.betwixt.io.BeanWriter; 
    public class WriteApp { 
    /** 
    * 创建一个例子Bean，并将它转化为XML. 
    */ 
    public static final void main(String [] args) throws Exception { 
      // 先创建一个StringWriter，我们将把它写入为一个字符串     
      StringWriter outputWriter = new StringWriter(); 
      // Betwixt在这里仅仅是将Bean写入为一个片断 
      // 所以如果要想完整的XML内容，我们应该写入头格式 
      outputWriter.write(“<&＃63;xml version='1.0′ encoding='UTF-8′ &＃63;>\n”); 
      // 创建一个BeanWriter，其将写入到我们预备的stream中 
      BeanWriter beanWriter = new BeanWriter(outputWriter); 
      // 配置betwixt 
      // 更多详情请参考java docs 或最新的文档 
      beanWriter.getXMLIntrospector().getConfiguration().setAttributesForPrimitives(false); 
      beanWriter.getBindingConfiguration().setMapIDs(false); 
      beanWriter.enablePrettyPrint(); 
      // 如果这个地方不传入XML的根节点名，Betwixt将自己猜测是什么 
      // 但是让我们将例子Bean名作为根节点吧 
      beanWriter.write(“person”, new PersonBean(“John Smith”, 21)); 
      //输出结果 
      System.out.println(outputWriter.toString()); 
      // Betwixt写的是片断而不是一个文档，所以不要自动的关闭掉writers或者streams， 
      //但这里仅仅是一个例子，不会做更多事情，所以可以关掉 
      outputWriter.close(); 
      } 
    } 
  //2、 将XML转化为JavaBean 
    import java.io.StringReader; 
    import org.apache.commons.betwixt.io.BeanReader; 
    public class ReadApp { 
    public static final void main(String args[]) throws Exception{ 
      // 先创建一个XML，由于这里仅是作为例子，所以我们硬编码了一段XML内容 
      StringReader xmlReader = new StringReader( 
      "<&＃63;xml version='1.0′ encoding='UTF-8′ &＃63;> 25James Smith"); 
      //创建BeanReader 
      BeanReader beanReader = new BeanReader(); 
      //配置reader 
      beanReader.getXMLIntrospector().getConfiguration().setAttributesForPrimitives(false); 
      beanReader.getBindingConfiguration().setMapIDs(false); 
      //注册beans，以便betwixt知道XML将要被转化为一个什么Bean 
      beanReader.registerBeanClass("person", PersonBean.class); 
      //现在我们对XML进行解析 
      PersonBean person = (PersonBean) beanReader.parse(xmlReader); 
      //输出结果 
      System.out.println(person); 
      } 
    }

//Base64编解码 
  private static String encodeTest(String str){ 
      Base64 base64 = new Base64(); 
      try { 
        str = base64.encodeToString(str.getBytes("UTF-8")); 
      } catch (UnsupportedEncodingException e) { 
        e.printStackTrace(); 
      } 
        System.out.println("Base64 编码后："+str); 
      return str; 
    } 
   
    private static void decodeTest(String str){ 
      Base64 base64 = new Base64(); 
      //str = Arrays.toString(Base64.decodeBase64(str)); 
      str = new String(Base64.decodeBase64(str)); 
      System.out.println("Base64 解码后："+str); 
    }

/** 
      * 得到集合里按顺序存放的key之后的某一Key 
      */ 
      OrderedMap map = new LinkedMap(); 
      map.put("FIVE", "5"); 
      map.put("SIX", "6"); 
      map.put("SEVEN", "7"); 
      map.firstKey(); // returns "FIVE" 
      map.nextKey("FIVE"); // returns "SIX" 
      map.nextKey("SIX"); // returns "SEVEN"  
     
      /** 
      * 通过key得到value 
      * 通过value得到key 
      * 将map里的key和value对调 
      */ 
     
      BidiMap bidi = new TreeBidiMap(); 
      bidi.put("SIX", "6"); 
      bidi.get("SIX"); // returns "6" 
      bidi.getKey("6"); // returns "SIX" 
      //    bidi.removeValue("6"); // removes the mapping 
      BidiMap inverse = bidi.inverseBidiMap(); // returns a map with keys and values swapped 
      System.out.println(inverse); 
   
      /** 
       * 得到两个集合中相同的元素 
       */ 
      List list1 = new ArrayList(); 
      list1.add("1"); 
      list1.add("2"); 
      list1.add("3"); 
      List list2 = new ArrayList(); 
      list2.add("2"); 
      list2.add("3"); 
      list2.add("5"); 
      Collection c = CollectionUtils.retainAll(list1, list2); 
      System.out.println(c);

//创建压缩对象 
    ZipArchiveEntry entry = new ZipArchiveEntry("CompressTest"); 
     //要压缩的文件 
     File f=new File("e:\\test.pdf"); 
     FileInputStream fis=new FileInputStream(f); 
     //输出的对象 压缩的文件 
     ZipArchiveOutputStream zipOutput=new ZipArchiveOutputStream(new File("e:\\test.zip"));  
     zipOutput.putArchiveEntry(entry); 
     int i=0,j; 
     while((j=fis.read()) != -1) 
     {  
      zipOutput.write(j); 
      i++; 
      System.out.println(i); 
     } 
     zipOutput.closeArchiveEntry(); 
     zipOutput.close(); 
     fis.close();

//举一个Properties的简单例子 
  # usergui.properties 
  colors.background = #FFFFFF 
  colors.foreground = #000080 
  window.width = 500 
  window.height = 300 
   
  PropertiesConfiguration cOnfig= new PropertiesConfiguration("usergui.properties"); 
  config.setProperty("colors.background", "#000000); 
  config.save(); 
   
  config.save("usergui.backup.properties);//save a copy 
  Integer integer = config.getInteger("window.width");

import javax.sql.DataSource; 
  import java.sql.Connection; 
  import java.sql.Statement; 
  import java.sql.ResultSet; 
  import java.sql.SQLException; 
   
  import org.apache.commons.pool.ObjectPool; 
  import org.apache.commons.pool.impl.GenericObjectPool; 
  import org.apache.commons.dbcp.ConnectionFactory; 
  import org.apache.commons.dbcp.PoolingDataSource; 
  import org.apache.commons.dbcp.PoolableConnectionFactory; 
  import org.apache.commons.dbcp.DriverManagerConnectionFactory; 
  //官方示例 
  public class PoolingDataSources { 
   
    public static void main(String[] args) { 
      System.out.println("加载jdbc驱动"); 
      try { 
      Class.forName("oracle.jdbc.driver.OracleDriver"); 
      } catch (ClassNotFoundException e) { 
      e.printStackTrace(); 
      } 
      System.out.println("Done."); 
      // 
      System.out.println("设置数据源"); 
      DataSource dataSource = setupDataSource("jdbc:oracle:thin:@localhost:1521:test"); 
      System.out.println("Done."); 
       
      // 
      Connection cOnn= null; 
      Statement stmt = null; 
      ResultSet rset = null; 
       
      try { 
      System.out.println("Creating connection."); 
      cOnn= dataSource.getConnection(); 
      System.out.println("Creating statement."); 
      stmt = conn.createStatement(); 
      System.out.println("Executing statement."); 
      rset = stmt.executeQuery("select * from person"); 
      System.out.println("Results:"); 
      int numcols = rset.getMetaData().getColumnCount(); 
      while(rset.next()) { 
      for(int i=0;i<=numcols;i++) { 
      System.out.print("\t" + rset.getString(i)); 
      } 
      System.out.println(""); 
      } 
      } catch(SQLException e) { 
      e.printStackTrace(); 
      } finally { 
      try { if (rset != null) rset.close(); } catch(Exception e) { } 
      try { if (stmt != null) stmt.close(); } catch(Exception e) { } 
      try { if (conn != null) conn.close(); } catch(Exception e) { } 
      } 
      } 
   
    public static DataSource setupDataSource(String connectURI) { 
      //设置连接地址 
      ConnectionFactory cOnnectionFactory= new DriverManagerConnectionFactory( 
          connectURI, null); 
   
      // 创建连接工厂 
      PoolableConnectionFactory poolableCOnnectionFactory= new PoolableConnectionFactory( 
          connectionFactory); 
   
      //获取GenericObjectPool 连接的实例 
      ObjectPool cOnnectionPool= new GenericObjectPool( 
          poolableConnectionFactory); 
   
      // 创建 PoolingDriver 
      PoolingDataSource dataSource = new PoolingDataSource(connectionPool); 
       
      return dataSource; 
    } 
  }

import org.apache.commons.dbutils.DbUtils; 
  import org.apache.commons.dbutils.QueryRunner; 
  import org.apache.commons.dbutils.handlers.BeanListHandler; 
  import java.sql.Connection; 
  import java.sql.DriverManager; 
  import java.sql.SQLException; 
  import java.util.List; 
  //转换成list 
  public class BeanLists { 
    public static void main(String[] args) { 
      Connection cOnn= null; 
      String url = "jdbc:mysql://localhost:3306/ptest"; 
      String jdbcDriver = "com.mysql.jdbc.Driver"; 
      String user = "root"; 
      String password = "ptest"; 
   
      DbUtils.loadDriver(jdbcDriver); 
      try { 
        cOnn= DriverManager.getConnection(url, user, password); 
        QueryRunner qr = new QueryRunner(); 
        List results = (List) qr.query(conn, "select id,name from person", new BeanListHandler(Person.class)); 
        for (int i = 0; i 

//用commons email发送邮件 
  public static void main(String args[]){ 
      Email email = new SimpleEmail(); 
      email.setHostName("smtp.googlemail.com"); 
      email.setSmtpPort(465); 
      email.setAuthenticator(new DefaultAuthenticator("username", "password")); 
      email.setSSLOnConnect(true); 
      email.setFrom("user@gmail.com"); 
      email.setSubject("TestMail"); 
      email.setMsg("This is a test mail ... :-)"); 
      email.addTo("foo@bar.com"); 
      email.send(); 
    }

//官方示例： 
  //* 检查请求是否含有上传文件 
    // Check that we have a file upload request 
    boolean isMultipart = ServletFileUpload.isMultipartContent(request); 
   
    //现在我们得到了items的列表 
   
    //如果你的应用近于最简单的情况，上面的处理就够了。但我们有时候还是需要更多的控制。 
    //下面提供了几种控制选择： 
    // Create a factory for disk-based file items 
    DiskFileItemFactory factory = new DiskFileItemFactory(); 
   
    // Set factory constraints 
    factory.setSizeThreshold(yourMaxMemorySize); 
    factory.setRepository(yourTempDirectory); 
   
    // Create a new file upload handler 
    ServletFileUpload upload = new ServletFileUpload(factory); 
   
    // 设置最大上传大小 
    upload.setSizeMax(yourMaxRequestSize); 
   
    // 解析所有请求 
    List /* FileItem */ items = upload.parseRequest(request); 
   
    // Create a factory for disk-based file items 
    DiskFileItemFactory factory = new DiskFileItemFactory( 
        yourMaxMemorySize, yourTempDirectory); 
   
    //一旦解析完成，你需要进一步处理item的列表。 
    // Process the uploaded items 
    Iterator iter = items.iterator(); 
    while (iter.hasNext()) { 
      FileItem item = (FileItem) iter.next(); 
   
      if (item.isFormField()) { 
        processFormField(item); 
      } else { 
        processUploadedFile(item); 
      } 
    } 
   
    //区分数据是否为简单的表单数据，如果是简单的数据： 
    // processFormField 
    if (item.isFormField()) { 
      String name = item.getFieldName(); 
      String value = item.getString(); 
      //...省略步骤 
    } 
   
    //如果是提交的文件： 
    // processUploadedFile 
    if (!item.isFormField()) { 
      String fieldName = item.getFieldName(); 
      String fileName = item.getName(); 
      String cOntentType= item.getContentType(); 
      boolean isInMemory = item.isInMemory(); 
      long sizeInBytes = item.getSize(); 
      //...省略步骤 
    } 
   
    //对于这些item，我们通常要把它们写入文件，或转为一个流 
    // Process a file upload 
    if (writeToFile) { 
      File uploadedFile = new File(...); 
      item.write(uploadedFile); 
    } else { 
      InputStream uploadedStream = item.getInputStream(); 
      //...省略步骤 
      uploadedStream.close(); 
    } 
   
    //或转为字节数组保存在内存中： 
    // Process a file upload in memory 
    byte[] data = item.get(); 
    //...省略步骤 
    //如果这个文件真的很大，你可能会希望向用户报告到底传了多少到服务端，让用户了解上传的过程 
    //Create a progress listener 
    ProgressListener progressListener = new ProgressListener(){ 
      public void update(long pBytesRead, long pContentLength, int pItems) { 
        System.out.println("We are currently reading item " + pItems); 
        if (pCOntentLength== -1) { 
          System.out.println("So far, " + pBytesRead + " bytes have been read."); 
        } else { 
          System.out.println("So far, " + pBytesRead + " of " + pContentLength 
                   + " bytes have been read."); 
        } 
      } 
    }; 
    upload.setProgressListener(progressListener);

//GET方法 
  import java.io.IOException; 
  import org.apache.commons.httpclient.*; 
  import org.apache.commons.httpclient.methods.GetMethod; 
  import org.apache.commons.httpclient.params.HttpMethodParams; 
   
  public class GetSample{ 
    public static void main(String[] args) { 
      // 构造HttpClient的实例 
      HttpClient httpClient = new HttpClient(); 
      // 创建GET方法的实例 
      GetMethod getMethod = new GetMethod("http://www.ibm.com"); 
      // 使用系统提供的默认的恢复策略 
      getMethod.getParams().setParameter(HttpMethodParams.RETRY_HANDLER, 
          new DefaultHttpMethodRetryHandler()); 
      try { 
        // 执行getMethod 
        int statusCode = httpClient.executeMethod(getMethod); 
        if (statusCode != HttpStatus.SC_OK) { 
          System.err.println("Method failed: " 
              + getMethod.getStatusLine()); 
        } 
        // 读取内容 
        byte[] respOnseBody= getMethod.getResponseBody(); 
        // 处理内容 
        System.out.println(new String(responseBody)); 
      } catch (HttpException e) { 
        // 发生致命的异常，可能是协议不对或者返回的内容有问题 
        System.out.println("Please check your provided http address!"); 
        e.printStackTrace(); 
      } catch (IOException e) { 
        // 发生网络异常 
        e.printStackTrace(); 
      } finally { 
        // 释放连接 
        getMethod.releaseConnection(); 
      } 
    } 
  } 
   
  //POST方法 
  import java.io.IOException; 
  import org.apache.commons.httpclient.*; 
  import org.apache.commons.httpclient.methods.PostMethod; 
  import org.apache.commons.httpclient.params.HttpMethodParams; 
   
  public class PostSample{ 
    public static void main(String[] args) { 
      // 构造HttpClient的实例 
      HttpClient httpClient = new HttpClient(); 
      // 创建POST方法的实例 
      String url = "http://www.oracle.com/"; 
      PostMethod postMethod = new PostMethod(url); 
      // 填入各个表单域的值 
      NameValuePair[] data = { new NameValuePair("id", "youUserName"), 
      new NameValuePair("passwd", "yourPwd") }; 
      // 将表单的值放入postMethod中 
      postMethod.setRequestBody(data); 
      // 执行postMethod 
      int statusCode = httpClient.executeMethod(postMethod); 
      // HttpClient对于要求接受后继服务的请求，象POST和PUT等不能自动处理转发 
      // 301或者302 
      if (statusCode == HttpStatus.SC_MOVED_PERMANENTLY ||  
      statusCode == HttpStatus.SC_MOVED_TEMPORARILY) { 
        // 从头中取出转向的地址 
        Header locatiOnHeader= postMethod.getResponseHeader("location"); 
        String location = null; 
        if (locationHeader != null) { 
         location = locationHeader.getValue(); 
         System.out.println("The page was redirected to:" + location); 
        } else { 
         System.err.println("Location field value is null."); 
        } 
        return; 
      } 
    } 
  }

//1．读取Stream 
   
  //标准代码： 
  InputStream in = new URL( "http://jakarta.apache.org" ).openStream(); 
  try { 
      InputStreamReader inR = new InputStreamReader( in ); 
      BufferedReader buf = new BufferedReader( inR ); 
      String line; 
      while ( ( line = buf.readLine() ) != null ) { 
       System.out.println( line ); 
      } 
   } finally { 
    in.close(); 
   } 
   
  //使用IOUtils 
   
  InputStream in = new URL( "http://jakarta.apache.org" ).openStream(); 
  try { 
    System.out.println( IOUtils.toString( in ) ); 
  } finally { 
    IOUtils.closeQuietly(in); 
  } 
   
  //2．读取文件 
  File file = new File("/commons/io/project.properties"); 
  List lines = FileUtils.readLines(file, "UTF-8"); 
  //3．察看剩余空间 
  long freeSpace = FileSystemUtils.freeSpace("C:/");

// 1 合并两个数组: org.apache.commons.lang. ArrayUtils 
    // 有时我们需要将两个数组合并为一个数组，用ArrayUtils就非常方便，示例如下： 
    private static void testArr() { 
      String[] s1 = new String[] { "1", "2", "3" }; 
      String[] s2 = new String[] { "a", "b", "c" }; 
      String[] s = (String[]) ArrayUtils.addAll(s1, s2); 
      for (int i = 0; i >" + str.length()); 
   
    } 
    //2 截取从from开始字符串 
    StringUtils.substringAfter("SELECT * FROM PERSON ", "from"); 
    //3 判断该字符串是不是为数字(0~9)组成，如果是，返回true 但该方法不识别有小数点和 请注意。 
    StringUtils.isNumeric("454534"); //返回true 
    //4.取得类名 
      System.out.println(ClassUtils.getShortClassName(Test.class)); 
      //取得其包名 
      System.out.println(ClassUtils.getPackageName(Test.class)); 
      
      //5.NumberUtils 
      System.out.println(NumberUtils.stringToInt("6")); 
      //6.五位的随机字母和数字 
      System.out.println(RandomStringUtils.randomAlphanumeric(5)); 
      //7.StringEscapeUtils 
      System.out.println(StringEscapeUtils.escapeHtml("")); 
      //输出结果为 
      System.out.println(StringEscapeUtils.escapeJava("String")); 
      
      //8.StringUtils,判断是否是空格字符 
      System.out.println(StringUtils.isBlank("  ")); 
      //将数组中的内容以,分隔 
      System.out.println(StringUtils.join(test,",")); 
      //在右边加下字符,使之总长度为6 
      System.out.println(StringUtils.rightPad("abc", 6, 'T')); 
      //首字母大写 
      System.out.println(StringUtils.capitalize("abc")); 
      //Deletes all whitespaces from a String 删除所有空格 
      System.out.println( StringUtils.deleteWhitespace("  ab c ")); 
      //判断是否包含这个字符 
      System.out.println( StringUtils.contains("abc", "ba")); 
      //表示左边两个字符 
      System.out.println( StringUtils.left("abc", 2)); 
      System.out.println(NumberUtils.stringToInt("33"));

import org.apache.commons.logging.Log; 
  import org.apache.commons.logging.LogFactory; 
   
    public class CommonLogTest { 
     private static Log log = LogFactory.getLog(CommonLogTest.class); 
     //日志打印 
     public static void main(String[] args) { 
       log.error("ERROR"); 
       log.debug("DEBUG"); 
       log.warn("WARN"); 
       log.info("INFO"); 
       log.trace("TRACE"); 
     System.out.println(log.getClass()); 
     } 
   
    }

// 获取日期验证 
     DateValidator validator = DateValidator.getInstance(); 
   
     // 验证/转换日期 
     Date fooDate = validator.validate(fooString, "dd/MM/yyyy"); 
     if (fooDate == null) { 
       // 错误 不是日期 
       return; 
     }

// 设置参数 
     boolean caseSensitive = false; 
     String regex1  = "^([A-Z]*)(&＃63;:\\-)([A-Z]*)*$" 
     String regex2  = "^([A-Z]*)$"; 
     String[] regexs = new String[] {regex1, regex1}; 
   
     // 创建验证 
     RegexValidator validator = new RegexValidator(regexs, caseSensitive); 
   
     // 验证返回boolean 
     boolean valid = validator.isValid("abc-def"); 
   
     // 验证返回字符串 
     String result = validator.validate("abc-def"); 
   
     // 验证返回数组 
     String[] groups = validator.match("abc-def");

 
     
       
     
     
     
   
   
  添加姓名验证. 
   
   
     
       
     
     
       
        
          
        
        
          
        
       
     
  

Excerpts from org.apache.commons.validator.RequiredNameTest 
//加载验证配置文件 
InputStream in = this.getClass().getResourceAsStream("validator-name-required.xml"); 
 
ValidatorResources resources = new ValidatorResources(in); 
//这个是自己创建的bean 我这里省略了 
Name name = new Name(); 
 
Validator validator = new Validator(resources, "nameForm"); 
//设置参数 
validator.setParameter(Validator.BEAN_PARAM, name); 
 
 
Map results = null; 
//验证 
results = validator.validate(); 
 
if (results.get("firstName") == null) { 
  //验证成功 
} else { 
  //有错误   int errors = ((Integer)results.get("firstName")).intValue(); 
}