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Mon, 25 Sep 2006 15:33:00 GMT

摘要: 使用XStream�q�行POJO和xml之间的�{�? XStream是一个开源项目，利用它可以方便的�q�行java对象和xml之间�q�行转换�Q�从而在��试�Q�服务器讄��{�方面有很好的应用�? 先徏两个java对象 1.Adress�c? package xml_chb; public ... 阅读全文

扬州�?/a> 2006-09-25 23:33 发表评论

Sun, 24 Sep 2006 15:41:00 GMT

dom4j学习�ȝ��Q�二�Q?/h4>

�Q�一�Q�移除节点及属�?/strong>

     /** */ /** �U�除节点和属性的操作
     * @throws DocumentException
      */
     public void RemoveOperator() throws DocumentException ... {
         // 待生成xml的字�W�串
        String str = " Java100 "
             + " Society security130 "
             + " chbboy " ;
         // 生成一个Document
        Document document = DocumentHelper.parseText(str);

        Element root = document.getRootElement();
         // 删除�c�d��为society的book节点
        Element book_society = (Element)document.selectSingleNode( " //book[@type='society'] " );
        root.remove(book_society);
        System.out.println( " 1。正��的删除了类型�ؓsociety的book节点 " );
        System.out.println(document.asXML());

         // 删除sex节点
        Element sex = (Element)root.selectSingleNode( " //sex " );

         // 从root节点删除
        root.remove(sex);
        System.out.println( " 2。这��h��不能删除sex节点�?/span> " );
        System.out.println(document.asXML());

         // 从author节点删除
        root.element( " author " ).remove(sex);
        System.out.println( " 3。这样就可以正确删除sex节点 " );
        System.out.println(document.asXML());

         // 删除属�?/span>
        Attribute type = root.element( " book " ).attribute( " type " );
        root.element( " book " ).remove(type);
        System.out.println( " 4。正��删除book节点的type属�?/span> " );
        System.out.println(document.asXML());
    }

输出�l�果为：

1。正��的删除了类型�ؓsociety的book节点

Java100chbboy
2。这��h��不能删除sex节点�?br />
Java100chbboy
3。这样就可以正确删除sex节点

Java100chb
4。正��删除book节点的type属�?br />
Java100chb

分析�Q?/strong>

�W�二个输出结果不能删除sex节点�Q�我们需要看dom4j的API

remove

public boolean remove(Element element)

Removes the given Element if the node is an immediate child of this branch. If the given node is not an immediate child of this branch then the Node.detach()method should be used instead.

Parameters:

element - is the element to be removed

Returns:

true if the element was removed

从中我们可以看出�Q�remove只能用在它自��q��直接孩子节点上，不能用在孙子节点上，因�ؓsex节点不是root节点的直接孩子节点，所以不能删除；而sex节点却是author节点的直接孩子节点，所以第三个输出可以删除�?/p>
�Q�二�Q�将两个Document合�ƈ��Z��个Document

先看一个错误的情况

�Q?�Q��用add()�Ҏ��d��

public void CombineDocument() throws DocumentException ... {
         // 待生成两个Document的字�W�串
        String str_book = " Java100 "
             + " Society security130 "
             + " " ;
        String str_author = " chbboy " ;

         // 生成两个Document
        Document doc_book = DocumentHelper.parseText(str_book);
        Document doc_author = DocumentHelper.parseText(str_author);

         // 取出doc_author的author节点�Q�添加到doc_book的根�l�点
        Element author = (Element)doc_author.selectSingleNode( " //author " );
        doc_book.getRootElement().add(author);
        System.out.println(doc_book.asXML());
    }

调用CombineDocument函数�Q�会出现以下错误�Q?/p>
org.dom4j.IllegalAddException: The node "org.dom4j.tree.DefaultElement@17bd6a1 [Element: ]" could not be added to the element "root" because: The Node already has an existing parent of "root"
at org.dom4j.tree.AbstractElement.addNode(AbstractElement.java:1521)
at org.dom4j.tree.AbstractElement.add(AbstractElement.java:1002)
at xml_chb.dom4j_chb.CombineDocument(dom4j_chb.java:189)
at xml_chb.dom4j_chb.main(dom4j_chb.java:199)
Exception in thread "main"

��x��C�author节点已经有一个root节点了，不能再添加到另一个节点上厅R�?/p>
�Q?�Q��用appendContent()�Ҏ��

卛_��doc_book.getRootElement().add(author);

改�ؓ�Q�doc_book.getRootElement().appendContent(author);

输出�l�果为：

Java100
Society security130
chbboy

可以看出�Q�缺��了author节点�Q�只是把author节点的子节点��d��上去了，但是由此可见�Q�appendContent�Ҏ��是有希望的�?/p>
我们看一下dom4j的API:

appendContent

public void appendContent(Branch branch)

Appends the content of the given branch to this branch instance. This method behaves like the Collection.addAll(java.util.Collection) method.

Parameters:

branch - is the branch whose content will be added to me.

�Q?�Q��用正��的appendContent�Ҏ��

��：Element author=(Element)doc_author.selectSingleNode("http://author");

doc_book.getRootElement().appendContent(author);

改�ؓ�Q�doc_book.getRootElement().appendContent(doc_author.getRootElement());

输出�Q?/p>

Java100
Society security130
chbboy

是正��结�?/p>
�Q?�Q�另一�U�可行的�Ҏ��

public void CombineDocument() throws DocumentException ... {
         // 待生成两个Document的字�W�串
        String str_book = " Java100 "
             + " Society security130 "
             + " " ;
        String str_author = " chbboy " ;

         // 生成两个Document
        Document doc_book = DocumentHelper.parseText(str_book);
        Document doc_author = DocumentHelper.parseText(str_author);

         // 新生成一个Document
        Element author = DocumentHelper.createElement( " author " );
        author.appendContent((Element)doc_author.selectSingleNode( " //author " ));
         // 当前author��无父节点，所以可以��用add�Ҏ��d��
        doc_book.getRootElement().add(author);

        System.out.println(doc_book.asXML());
    }

扬州�?/a> 2006-09-24 23:41 发表评论

Sat, 23 Sep 2006 18:10:00 GMT

dom4j学习�ȝ��Q�一�Q��?/h4>
�Q�一�Q�创建Document的基本操�?/strong>

/**
* xml基本操作
*/
public void BaseOperation(){
  //创徏一个document
  Document document=DocumentHelper.createDocument();
  //创徏根结�?br />  Element root=document.addElement("root");
  //为根�l�点��d��一个book节点
  Element book1=root.addElement("book");
  //为book1��d��属性type
  book1.addAttribute("type","science");
  //为book1��d��name子节�?br />  Element name1=book1.addElement("Name");
  //�q�设�|�其name�?Java"
  name1.setText("Java");
  //为book1创徏一个price节点,�q�设其�h��gؓ100
  book1.addElement("price").setText("100");

  //为根�l�点��d��W�二个book节点�Q��ƈ讄��该book节点的type属�?br />  Element book2=root.addElement("book").addAttribute("type","science");
  //为book1��d��name子节�?br />  Element name2=book2.addElement("Name");
  //�q�设�|�其name�?Oracle"
  name2.setText("Oracle");
  //为book1创徏一个price节点,�q�设其�h��gؓ200
  book2.addElement("price").setText("200");

  //输出xml
  System.out.println(document.asXML());
}

调用BaseOperation�Q�输出结果�ؓ�Q?/p>

  Java
  100

  Oracle
  200

�Q�二�Q�根据一个符合Document格式的字�W�串来生成一个Document

/**��字�W�串转化为Document
* @param str 输入的字�W�串
* @return 生成的document
* @throws DocumentException
*/
public Document parserStrtoDocument(String str) throws DocumentException{
  Document document=DocumentHelper.parseText(str);
  return document;
}

调用�C�Z��Q?/p>
String str="Java100";

  Document document = parserStrtoDocument(str);
  System.out.println(document.asXML());

输出�l�果为：

  Java
  100

�Q�三�Q�取得xml节点属性的基本�Ҏ��

/**
* 取得xml的节点和属性的�?br /> * @throws DocumentException
*/
public void getBaseInfofromDocument() throws DocumentException{
  String str="Java100";
  //生成一个Document
  Document document = DocumentHelper.parseText(str);
  //取得根结�?br />  Element root=document.getRootElement();
  //取得book节点
  Element book=root.element("book");
  //取得book节点的type属性的�?br />  String type=book.attributeValue("type");
  //取得Name节点
  Element name=book.element("Name");
  //取得书名
  String bookname=name.getText();
  //取得书的价钱
  int price=Integer.parseInt(book.element("price").getText());

  //输出书目信息
  System.out.println("书名�Q?+bookname);
  System.out.println("所属类别："+type);
  System.out.println("��h��Q?+price);
}

调用getBaseInfofromDocument�Q�输出结果�ؓ�Q?/p>
书名�Q�Java
所属类别：science
��h��Q?00

�Q�四�Q�利用�P代，xpath取得节点及其属性�?/strong>

/**利用�q�代�Q�xpath取得xml的节点及其属性�?br /> * @throws DocumentException
*/
public void getComplexInfofromDocument() throws DocumentException{

  String str="Java100"
   +"Oracle120"
   +"Society security130"
   +"chb";
  //生成一个Document
  Document document = DocumentHelper.parseText(str);

  //提取�c�d��?society"的书
  //此处需要添加支持xpath的jar包，详细见备�?br />  Element society_book=(Element)document.selectSingleNode("/root/book[@type='society']");
  System.out.println(society_book.asXML());

  //提取��h��节点的列�?br />  System.out.println("-----------��h��列表-------------");
  List price=document.selectNodes("http://price");
  for(int i=0;i   Element elem_price=(Element)price.get(i);
   System.out.println(elem_price.getText());
  }

  //循环根结点下的所有节点，若当前节点�ؓbook�Q�则输出�q�本书的详细信息
  System.out.println("-------------书目详情------------");
  System.out.println("书名\t\t�c�d��\t\t��h��");
  Element root=document.getRootElement();
  Iterator iterator=root.elementIterator();
  while(iterator.hasNext()){
   Element element=(Element)iterator.next();
   if(element.getName().equals("book")){
    System.out.print(element.element("Name").getText()+"\t");
    System.out.print(element.attributeValue("type")+"\t\t");
    System.out.print(element.element("price").getText()+"\n");
   }
  }

  //查找作者姓�?br />  Element author=(Element)document.selectSingleNode("http://author");
  System.out.println("---------"+author.element("name").getText()+"----------");
  //提取作者的所有书目名�U?br />  Iterator iterator_book=root.elementIterator("book");
  while(iterator_book.hasNext()){
   Element book=(Element)iterator_book.next();
   System.out.print(book.element("Name").getText()+"\t");
  }

  //属性�P�?br />  System.out.println("\n-------属性�P�?-------");
  String str1="";
  Document document1=DocumentHelper.parseText(str1);
  //开始�P�?br />  Iterator iterator_attribute=document1.getRootElement().attributeIterator();
  while(iterator_attribute.hasNext()){
   //提取当前属�?br />   Attribute attribute=(Attribute)iterator_attribute.next();
   System.out.println(attribute.getName()+":"+attribute.getValue());
  }
}

调用getComplexInfofromDocument�Q�输出结果�ؓ�Q?/p>
Society security130
-----------��h��列表-------------
100
120
130
-------------书目详情------------
书名  �c�d��  ��h��
Java science  100
Oracle science  120
Society security society  130
---------chb----------
Java Oracle Society security
-------属性�P�?-------
type:science
name:Java
price:100

备注�Q�调用该�Ҏ��之前�Q�应该先向工�E�中��d��支持xpath的jar包，否则�Q�会出现以下错误�Q?/strong>

java.lang.NoClassDefFoundError: org/jaxen/JaxenException
at org.dom4j.DocumentFactory.createXPath(DocumentFactory.java:230)
at org.dom4j.tree.AbstractNode.createXPath(AbstractNode.java:207)
at org.dom4j.tree.AbstractNode.selectSingleNode(AbstractNode.java:183)
at xml_chb.dom4j_chb.getComplexInfofromDocument(dom4j_chb.java:82)
at xml_chb.dom4j_chb.main(dom4j_chb.java:92)
Exception in thread "main"

只需要引入jaxen包就行了�Q�我使用的是hibernate包中的jaxen-1.1-beta-7.jar包�?/p>

扬州�?/a> 2006-09-24 02:10 发表评论

使用Hashtable对字�W�串�q�行��撞

Thu, 21 Sep 2006 08:25:00 GMT
1.在一些字�W�串数组中，�怼�有重复的记录�Q�比如手机号码，我们可以通过Hashtable来对其进行过�?br />public String[] checkArray(String[] str){
        Hashtable hash=new Hashtable();
        for(int i=0;i            if(!hash.containsKey(str[i]))
                hash.put(str[i], str[i]);
        }
        Enumeration enumeration=hash.keys();
        String[] str_new=new String[hash.size()];
        int i=0;
        while(enumeration.hasMoreElements()){
            str_new[i]=enumeration.nextElement().toString();
            i++;
        }
        return str_new;
    }
�C�Z��Q?br />        String[] mobile={"13811071500","13811071500","13811071501","13811071503","13811071501"};
        mobile=checkArray(mobile);
        for(int i=0;i            System.out.println(mobile[i]);
       输出�l�果为：
        13811071503
        13811071501
        13811071500
2.A,B均�ؓ字符串数�l�，扑և�在A中存在，而在B中不存在的字�W�串
    public String[] compareArray(String[] A,String[] B){
        Hashtable hash=new Hashtable();
        Hashtable hash_new=new Hashtable();
        for(int i=0;i            hash.put(B[i], B[i]);
        for(int i=0;i            if(!hash.containsKey(A[i]))
                hash_new.put(A[i], A[i]);
        }
        String[] C=new String[hash_new.size()];
        int i=0;
        Enumeration enumeration=hash_new.keys();
        while(enumeration.hasMoreElements()){
            C[i]=enumeration.nextElement().toString();
            i++;
        }
        return C;
    }
�C�Z��Q?br />        String[] mobile1={"13811071500","13811071501","13811071502","13811071503","13811071504"};
        String[] mobile2={"13811071500","13811071505","13811071502","13811071506","13811071504"};
        String[] mobile3=compareArray(mobile1,mobile2);
        for(int i=0;i            System.out.println(mobile[i]);
输出�l�果�Q?br />    13811071503
    13811071501
存在的问题：
每次都是倒序�Q�可以再对程序稍加改动，变成正序�?/font>

扬州�?/a> 2006-09-21 16:25 发表评论

Tue, 19 Sep 2006 14:29:00 GMT

在实际工作中�Q�常帔R��要设定数字的输出格式�Q�如以百分比的�Ş式输出，或者设定小��C��数等�Q�先�E�微�ȝ��如下�?br />主要使用的类�Q�java.text.DecimalFormat
1。实例化对象�Q�可以用如下两种�Ҏ��Q?br />DecimalFormat df=(DecimalFormat)NumberFormat.getInstance();
DecimalFormat df1=(DecimalFormat) DecimalFormat.getInstance();
因�ؓDecimalFormat�l�承自NumberFormat�?br />2。设定小��C��?br />�pȝ��默认��数位数�?�Q�如�Q?br />  DecimalFormat df=(DecimalFormat)NumberFormat.getInstance();
  System.out.println(df.format(12.3456789));
输出�Q?2.346
现在可以通过如下�Ҏ��把小��Cؓ设�ؓ两位�Q?br /> df.setMaximumFractionDigits(2);
  System.out.println(df.format(12.3456789));
则输��Zؓ�Q?2.35
3。将数字转化为百分比输出�Q�有如下两种�Ҏ��Q?br />(1)
df.applyPattern("##.##%");
  System.out.println(df.format(12.3456789));
  System.out.println(df.format(1));
  System.out.println(df.format(0.015));
输出分别为：1234.57% 100%    1.5%
(2)
df.setMaximumFractionDigits(2);
  System.out.println(df.format(12.3456789*100)+"%");
  System.out.println(df.format(1*100)+"%");
  System.out.println(df.format(0.015*100)+"%");
输出分别为：
1,234.57%   100%   1.5%
4。设�|�分�l�大��?br />   DecimalFormat df1=(DecimalFormat) DecimalFormat.getInstance();
  df1.setGroupingSize(2);
  System.out.println(df1.format(123456789));
输出�Q?,23,45,67,89
�q�可以通过df1.setGroupingUsed(false);来禁用分�l�设�|�，如：
   DecimalFormat df1=(DecimalFormat) DecimalFormat.getInstance();
  df1.setGroupingSize(2);
  df1.setGroupingUsed(false);
  System.out.println(df1.format(123456789));
输出�Q?23456789
5。设�|�小��Cؓ必须�?�?br /> DecimalFormat df2=(DecimalFormat) DecimalFormat.getInstance();
  df2.applyPattern("0.00");
  System.out.println(df2.format(1.2));
输出�Q?.20

扬州�?/a> 2006-09-19 22:29 发表评论

java中关于时间日期操作的常用函数

Mon, 18 Sep 2006 05:40:00 GMT
1.计算某一月䆾的最大天�?br />Calendar time=Calendar.getInstance();
time.clear();
time.set(Calendar.YEAR,year);
time.set(Calendar.MONTH,i-1);//注意,Calendar对象默认一月�ؓ0
int day=time.getActualMaximum(Calendar.DAY_OF_MONTH);//本月份的天数
2.Calendar和Date的�{�?br />(1) Calendar转化为Date
Calendar cal=Calendar.getInstance();
Date date=cal.getTime();
(2) Date转化为Calendar
Date date=new Date();
Calendar cal=Calendar.getInstance();
cal.setTime(date);
3.格式化输出日期时�?br />Date date=new Date();
SimpleDateFormat df=new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
System.out.println(df.format(date));
4.计算一�q�中的第几星�?br />(1)计算某一天是一�q�中的第几星�?br />Calendar cal=Calendar.getInstance();
cal.set(Calendar.YEAR, 2006);
cal.set(Calendar.MONTH, 8);
cal.set(Calendar.DAY_OF_MONTH, 3);
int weekno=cal.get(Calendar.WEEK_OF_YEAR);
(2)计算一�q�中的第几星期是几号
SimpleDateFormat df=new SimpleDateFormat("yyyy-MM-dd");
Calendar cal=Calendar.getInstance();
cal.set(Calendar.YEAR, 2006);
cal.set(Calendar.WEEK_OF_YEAR, 1);
cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
System.out.println(df.format(cal.getTime()));
输出:
2006-01-02
5.add()和roll()的用�?br />(1)add()�Ҏ��
SimpleDateFormat df=new SimpleDateFormat("yyyy-MM-dd");
Calendar cal=Calendar.getInstance();
cal.set(Calendar.YEAR, 2006);
cal.set(Calendar.MONTH, 8);
cal.set(Calendar.DAY_OF_MONTH, 3);
cal.add(Calendar.DATE, -4);
Date date=cal.getTime();
System.out.println(df.format(date));
cal.add(Calendar.DATE, 4);
date=cal.getTime();
System.out.println(df.format(date));
输出�Q?br />    2006-08-30
    2006-09-03
(2)roll�Ҏ��
cal.set(Calendar.YEAR, 2006);
cal.set(Calendar.MONTH, 8);
cal.set(Calendar.DAY_OF_MONTH, 3);
cal.roll(Calendar.DATE, -4);
date=cal.getTime();
System.out.println(df.format(date));
cal.roll(Calendar.DATE, 4);
date=cal.getTime();
System.out.println(df.format(date));
输出�Q?br />    2006-09-29
    2006-09-03
可见�Q?font color="#ff3300">roll()�Ҏ��在本月内循环�Q�一般��用add()�Ҏ��Q?/font>

扬州�?/a> 2006-09-18 13:40 发表评论

999久久久久久久久6666,亚洲精品视频在线,欧美精品久久一区二区三区

remove

appendContent

使用Hashtable对字�W�串�q�行���撞

java中关于时间日期操作的常用函数

使用Hashtable对字�W�串�q�行��撞