java对象转换xml

㈠ java中 inputStream怎样高效率的准换成xml和json对象，然后转换成map集合。

您好，提问者：
1、使用缓冲流：BufferedInputStream。
2、或者转为缓冲字符流：
BufferedReader br = new BufferedReader(new InputStreamReader(xx));

㈡ xstream如何将java对象转化成有cdata的xml

实体类要加注解

实体类要加注解
@XStreamAlias("msg")
{

=3196422897798539811L;

@XStreamAsAttribute
privateStringtoUid;
@XStreamAsAttribute
privateStringfromUid;
@XStreamAsAttribute
privateStringflag;
@XStreamAsAttribute
privateStringtime;
@XStreamAlias("content")
privateStringcontent;
@XStreamAlias("user")
privateStringuser;
//省略geter、seter
}
然后写个工具类
importcom.thoughtworks.xstream.XStream;
importcom.thoughtworks.xstream.io.xml.DomDriver;

publicclassSerializeXmlUtil{

/**
*java对象转化成xml字符串
*@paramobjjava对象实例
*@returnStringxml字符串
*/
(Objectobj){
//XStreamxstream=newXStream();
//直接用jaxpdom来解释
//XStreamxstream=newXStream(newDomDriver());
//指定编码解析器,直接用jaxpdom来解释
XStreamxstream=newXStream(newDomDriver("utf-8"));
//如果没有这句，xml中的根元素会是<包.类名>
//或者说：注解根本就没生效，所以的元素名就是类的属性
xstream.processAnnotations(obj.getClass());
StringBufferxmlstrbuf=newStringBuffer();
xmlstrbuf.append("<?xmlversion="1.0"?>");
xmlstrbuf.append("
");
xmlstrbuf.append(xstream.toXML(obj));
returnxmlstrbuf.toString();
}

/**
*将传入xml字符串转化为java对象
*@paramxmlstr
*@paramclsxml对应的class类
*@returnTxml对应的class类的实例对象
*调用的方法实例：PersonBeanperson=XmlUtil.toBean(xmlStr,PersonBean.class);
*/
publicstatic<T>TdeSerizalizeFromXml(Stringxmlstr,Class<T>cls)throwsException{
//注意：不是newXstream();否则报错：java.lang.NoClassDefFoundError:
//org/xmlpull/v1/XmlPullParserFactory
XStreamxstream=newXStream(newDomDriver());
xstream.processAnnotations(cls);
Tobj=(T)xstream.fromXML(xmlstr);
returnobj;
}
}

㈢ XStream将java对象转换为xml时，对象字段中的下划线“_”，转换后变成了两个

warning: [deprecation] XppDriver(com.thoughtworks.xstream.io.xml.XmlFriendlyReplacer) in com.thoughtworks.xstream.io.xml.XppDriver has been deprecated

已经过时的方法，所以，不会调用此方法。

㈣ 用Java怎么把String类型的字符串转化为XML格式输出

JXmlSerializable 是一个利用java反射，通过调用对象中所有以get（不区分大小写)开头的方法除去getClass方法,生成xml格式,希望与大家分享一下
下面是一个parent对象，包含两个child对象 生成的xml如下

Child类

1package xmlTest;
2
3import java.io.FileNotFoundException;
4import java.io.IOException;
5import java.io.PrintWriter;
6import java.lang.reflect.InvocationTargetException;
7public class Child extends JXmlSerializable {
8
9 private String _name;
10 private String _sex;
11 private int age;
12
13 public void setAge(int num) {
14 age = num;
15 }
16
17 public int getAge() {
18 return age;
19 }
20
21 public void setName(String name) {
22 _name = name;
23 }
24
25 public void setSex(String sex) {
26 _sex = sex;
27 }
28
29 public String getName() {
30 return _name;
31 }
32
33 public String getSex() {
34 return _sex;
35 }
36
37}
38
Parent类 1package xmlTest;
2
3import java.io.PrintWriter;
4import java.lang.reflect.Array;
5import java.util.*;
6
7public class Parent extends JXmlSerializable {
8
9 private String _name;
10 private String _sex;
11 private LinkedList list = new LinkedList();
12 private Vector vec = new Vector();
13 int age;
14
15 public void setAge(int num) {
16 age = num;
17 }
18
19 public int getAge() {
20 return age;
21 }
22
23 public void setName(String name) {
24 _name = name;
25 }
26
27 public void setSex(String sex) {
28 _sex = sex;
29 }
30
31 public String getName() {
32 return _name;
33 }
34
35 public String getSex() {
36 return _sex;
37 }
38
39 public void addChild(Child child) {
40 list.add(child);
41 vec.add(child);
42 }
43
44 public Child[] getChild() {
45
46 Child[] aa = new Child[vec.size()];
47 // list.toArray(aa);
48 vec.toArray(aa);
49 return aa;
50 }
51
52 public static void main(String[] args) {
53 // TODO Auto-generated method stub
54 try {
55 Parent pat = new Parent();
56 pat.setName("jack");
57 pat.setSex("male");
58 Child child1 = new Child();
59 child1.setName("tom");
60 child1.setSex("male");
61 pat.addChild(child1);
62 Child child2 = new Child();
63 child2.setName("Marie");
64 child2.setSex("female");
65 pat.addChild(child2);
66 pat.getChild();
67 PrintWriter out = new PrintWriter("abc.xml");
68 pat.toXmlSerial(out,0);
69 out.flush();
70
71 } catch (Exception e) {
72 e.printStackTrace();
73 }
74
75 }
76}
类 JXmlSerializable
1package xmlTest;
2
3import java.lang.reflect.Method;
4import java.lang.reflect.InvocationTargetException;
5import java.lang.reflect.Array;
6import java.io.PrintWriter;
7import java.io.IOException;
8public class JXmlSerializable {
9
10 public void toXmlSerial(PrintWriter out, int num)
11 throws InvocationTargetException, IllegalAccessException,
12 IOException {
13 out.write("<?xml version="1.0"?> ");
14 String head = "";
15 for (int i = 0; i < num; i++) {
16 head += " ";
17 }
18 out.write(head + "<" + this.getClass().getName() + "> ");
19 Method[] methods = this.getClass().getMethods();
20 for (int i = 0; i < methods.length; i++) {
21 Class[] paras = methods[i].getParameterTypes();
22 String name = methods[i].getName();
23 if (paras == null || paras.length == 0) {
24 if ((name.substring(0, 3).toLowerCase().equals("get"))
25 && !name.equals("getClass")) {
26 Object obj = methods[i].invoke(this, null);
27 getMethodXmlSerial(out, obj, methods[i], num);
28 }
29 }
30 }
31
32 out.write(head + "</" + this.getClass().getName() + "> ");
33
34 }
35
36 private void getMethodXmlSerial(PrintWriter out, Object obj, Method method,
37 int num) throws InvocationTargetException, IllegalAccessException,
38 IOException {
39 if (obj == null)
40 return;
41 String head = "";
42 for (int i = 0; i <= num; i++) {
43 head += " ";
44 }
45 if (obj.getClass().isArray()) {
46 for (int i = 0; i < Array.getLength(obj); i++) {
47 Object childobj = Array.get(obj, i);
48 if (childobj instanceof JXmlSerializable) {
49 ((JXmlSerializable) childobj).toXmlSerial(out, num + 1);
50 } else {
51 getMethodXmlSerial(out, childobj, method, num);
52 }
53 }
54 } else {
55 out.write(head + " <" + method.getName().substring(3) + "> ");
56 out.write(obj.toString());
57 out.write(" </" + method.getName().substring(3) + "> ");
58 }
59
60 }
61}

编译出来还可以，能够达到我的理想。

编译结果是

1<?xml version="1.0"?>
2<xmlTest.Parent>
3 <Name> jack </Name>
4 <Age> 0 </Age>
5 <Sex> male </Sex>
6<?xml version="1.0"?>
7 <xmlTest.Child>
8 <Name> tom </Name>
9 <Age> 0 </Age>
10 <Sex> male </Sex>
11 </xmlTest.Child>
12<?xml version="1.0"?>
13 <xmlTest.Child>
14 <Name> Marie </Name>
15 <Age> 0 </Age>
16 <Sex> female </Sex>
17 </xmlTest.Child>
18</xmlTest.Parent>
今天看了看java.beans包，发现了两个好东西，XMLEncoder和XMLDecoder。发现自己以前把从XML存取对象真是太费力气啦。做了小工具类，以后可以用用了。
1以下是引用片段：
2package com.imct.util;
3import java.beans.XMLDecoder;
4import java.beans.XMLEncoder;
5import java.io.File;
6import java.io.FileInputStream;
7import java.io.FileNotFoundException;
8import java.io.FileOutputStream;
9import java.io.IOException;
10import java.util.ArrayList;
11import java.util.List;
12/** *//**
13 * <title>使用XML文件存取可序列化的对象的类</title>
14 * <description>提供保存和读取的方法</description>
15 * @author 殷晋
16 * <right>清华大学汽车工程开发研究院@2005</right>
17 * @version 1.0
18 * 2005-8-5 16:44:49
19 */
20public class ObjectToXMLUtil
21{
22 /** *//**
23 * 把java的可序列化的对象(实现Serializable接口)序列化保存到XML文件里面,如果想一次保存多个可序列化对象请用集合进行封装
24 * 保存时将会用现在的对象原来的XML文件内容
25 * @param obj 要序列化的可序列化的对象
26 * @param fileName 带完全的保存路径的文件名
27 * @throws FileNotFoundException 指定位置的文件不存在
28 * @throws IOException 输出时发生异常
29 * @throws Exception 其他运行时异常
30 */
31 public static void objectXmlEncoder(Object obj,String fileName)
32 throws FileNotFoundException,IOException,Exception
33 {
34 //创建输出文件
35 File fo = new File(fileName);
36 //文件不存在,就创建该文件
37 if(!fo.exists())
38 {
39 //先创建文件的目录
40 String path = fileName.substring(0,fileName.lastIndexOf('.'));
41 File pFile = new File(path);
42 pFile.mkdirs();
43 }
44 //创建文件输出流
45 FileOutputStream fos = new FileOutputStream(fo);
46 //创建XML文件对象输出类实例
47 XMLEncoder encoder = new XMLEncoder(fos);
48 //对象序列化输出到XML文件
49 encoder.writeObject(obj);
50 encoder.flush();
51 //关闭序列化工具
52 encoder.close();
53 //关闭输出流
54 fos.close();
55 }
56 /** *//**
57 * 读取由objSource指定的XML文件中的序列化保存的对象,返回的结果经过了List封装
58 * @param objSource 带全部文件路径的文件全名
59 * @return 由XML文件里面保存的对象构成的List列表(可能是一个或者多个的序列化保存的对象)
60 * @throws FileNotFoundException 指定的对象读取资源不存在
61 * @throws IOException 读取发生错误
62 * @throws Exception 其他运行时异常发生
63 */
64 public static List objectXmlDecoder(String objSource)
65 throws FileNotFoundException,IOException,Exception
66 {
67 List objList = new ArrayList();
68 File fin = new File(objSource);
69 FileInputStream fis = new FileInputStream(fin);
70 XMLDecoder decoder = new XMLDecoder(fis);
71 Object obj = null;
72 try
73 {
74 while( (obj = decoder.readObject()) != null)
75 {
76 objList.add(obj);
77 }
78 }
79 catch (Exception e)
80 {
81 // TODO Auto-generated catch block
82 }
83 fis.close();
84 decoder.close();
85 return objList;
86 }
87}
88
89
90当然用Beans.instantiate也可以从文件中反序列化初对象