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(); }

您好，登录后才能下订单哦！

密码登录

忘记密码？

登录注册

获取短信验证码

其他方式登录

点击登录注册即表示同意《亿速云用户服务条款》

组件	功能介绍
BeanUtils	提供了对于JavaBean进行各种操作，克隆对象,属性等等.
Betwixt	XML与Java对象之间相互转换.
Codec	处理常用的编码方法的工具类包例如DES、SHA1、MD5、Base64等.
Collections	java集合框架操作.
Compress	java提供文件打包压缩类库.
Configuration	一个java应用程序的配置管理类库.
DBCP	提供数据库连接池服务.
DbUtils	提供对jdbc 的操作封装来简化数据查询和记录读取操作.
Email	java发送邮件对javamail的封装.
FileUpload	提供文件上传功能.
HttpClien	提供HTTP客户端与服务器的各种通讯操作. 现在已改成HttpComponents
IO	io工具的封装.
Lang	Java基本对象方法的工具类包如：StringUtils,ArrayUtils等等.
Logging	提供的是一个Java 的日志接口.
Validator	提供了客户端和服务器端的数据验证框架.

相关阅读