apache commons工具集 apache commons工具集代码详解

//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(“<?xml version='1.0′ encoding='UTF-8′ ?>\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( 
		    "<?xml version='1.0′ encoding='UTF-8′ ?> <person><age>25</age><name>James Smith</name></person>");
		//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<String> list1 = new ArrayList<String>();
list1.add("1");
list1.add("2");
list1.add("3");
List<String> list2 = new ArrayList<String>();
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 < results.size(); i++) {
				Person p = (Person) results.get(i);
				System.out.println("id:" + p.getId() + ",name:" + p.getName());
			}
		}
		catch (SQLException e) {
			e.printStackTrace();
		}
		finally {
			DbUtils.closeQuietly(conn);
		}
	}
}
public class Person{
	private Integer id;
	private String name;
	//省略set, get方法
}
import org.apache.commons.dbutils.DbUtils;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.MapListHandler;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.List;
import java.util.Map;
//转换成map 
public class MapLists {
	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 MapListHandler());
			for (int i = 0; i < results.size(); i++) {
				Map map = (Map) results.get(i);
				System.out.println("id:" + map.get("id") + ",name:" + map.get("name"));
			}
		}
		catch (SQLException e) {
			e.printStackTrace();
		}
		finally {
			DbUtils.closeQuietly(conn);
		}
	}
}

//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 < s.length; i++) {
		System.out.println(s[i]);
	}
	String str = ArrayUtils.toString(s);
	str = str.substring(1, str.length() - 1);
	System.out.println(str + ">>" + 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("<html>"));
//输出结果为<html> 
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]*)(?:\\-)([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");

<form-validation> 
  <global> 
    <validator name="required" 
     classname="org.apache.commons.validator.TestValidator" 
     method="validateRequired" 
     methodParams="java.lang.Object, org.apache.commons.validator.Field"/> 
  </global> 
  <formset> 
  </formset> 
</form-validation> 
 
添加姓名验证. 
 
<form-validation> 
  <global> 
    <validator name="required" 
     classname="org.apache.commons.validator.TestValidator" 
     method="validateRequired" 
     methodParams="java.lang.Object, org.apache.commons.validator.Field"/> 
  </global> 
  <formset> 
    <form name="nameForm"> 
     <field property="firstName" depends="required"> 
       <arg0 key="nameForm.firstname.displayname"/> 
     </field> 
     <field property="lastName" depends="required"> 
       <arg0 key="nameForm.lastname.displayname"/> 
     </field> 
    </form> 
  </formset> 
</form-validation>  

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();
}