Xml parsing: using dom4j APIs to perform CRUD on xml files (2)

Use dom4j APIs to perform CRUD (1) on the xml file. for details, see blog. csdn. NETqq_32059827articledetails51524330. Use dom4j APIs to perform CRUD (1) on the xml file, see blog #, and perform another exercise.

Package gz. itcast. a_dom4j_write; import java. io. file; import java. io. fileOutputStream; import java. util. iterator; import org. dom4j. document; import org. dom4j. export enthelper; import org. dom4j. element; import org. dom4j. io. outputFormat; import org. dom4j. io. SAXReader; import org. dom4j. io. XMLWriter; import org. junit. test;/*** classroom exercise: * 1. use dom4j APIs to generate the following xml files
 
  
   
    
Zhang San
   
   
    
Male
   
   
    
Computer class 1
   Guangzhou Tianhe District
  
  
   
    
Li Si
   
   
    
Female
   
   
    
Computer class 2
   Guangzhou Yuexiu District
  
 2. change the name of the student whose id is 2 to "Wang Li. delete student * @ author APPle **/public class Demo4 {/*** 1 with id 2. generate the specified xml document * @ throws Exception */@ Testpublic void test1 () throws Exception {// 1. memory creation xml Document doc = incluenthelper. createDocument (); // 2. write content. the first write is the root tag Element rootElem = doc. addElement ("Students"); // 2.1 add the label Element studentElem1 = rootElem. addElement ("Student"); // 2.2 add the attribute studentElem1.addAttribute ("id", "1"); // 2.3 add a tag And set the text studentElem1.addElement ("name "). setText ("zhang san"); studentElem1.addElement ("gender "). setText ("male"); studentElem1.addElement ("grade "). setText ("computer class 1"); studentElem1.addElement ("address "). setText ("Guangzhou Tianhe"); // 2.1 add the label Element studentElem2 = rootElem. addElement ("Student"); // 2.2 add the studentElem2.addAttribute ("id", "2"); // 2.3 add a label and set the text studentElem2.addElement ("name "). setText ("Li Si"); studentElem2.addElemen T ("gender "). setText ("female"); studentElem2.addElement ("grade "). setText ("computer class 2"); studentElem2.addElement ("address "). setText ("Guangzhou Yuexiu"); // 3. write all the changes to the doc once. Write the content to the xml file // 3.1 output location FileOutputStream out = new FileOutputStream ("d:/student. xml "); // 3.2 specify the format OutputFormat format = OutputFormat. createPrettyPrint (); // sets the encoding format. setEncoding ("UTF-8"); XMLWriter writer = new XMLWriter (out, format); // 3.3 write the content writer. write (doc); // 3.4 close the resource writer. close ();}/*** 2. change student name * @ throws Exception */@ Testpublic void test2 () throws Exception {// 1. the student Document doc = new SAXReader () with id 2 is found (). read (new File ("d:/student. xml "); // 1.1 find all Student labels Iterator
 
  
It = doc. getRootElement (). elementIterator ("Student"); while (it. hasNext () {Element stuElem = it. next (); // Student tag // 1.2 query if (stuElem. attributeValue ("id "). equals ("2") {stuElem. element ("name "). setText ("Wang Li"); // overwrite break ;}// 3.1 output position FileOutputStream out = new FileOutputStream ("d:/student. xml "); // 3.2 specify the format OutputFormat format = OutputFormat. createPrettyPrint (); // sets the encoding format. setEncoding ("UTF-8"); XMLWriter writer = new XMLWriter (out, format); // 3.3 write the content writer. write (doc); // 3.4 close the resource writer. close ();}/*** 3. delete student * @ throws Exception */@ Testpublic void test3 () throws Exception {// 1. the student Document doc = new SAXReader () with id 2 is found (). read (new File ("e:/student. xml "); // 1.1 find all Student labels Iterator
  
   
It = doc. getRootElement (). elementIterator ("Student"); while (it. hasNext () {Element stuElem = it. next (); // 1.2 query if (stuElem. attributeValue ("id "). equals ("2") {// 1.3 Delete this student tag stuElem. detach (); // suicide break;} // 3.1 output position FileOutputStream out = new FileOutputStream ("e:/student. xml "); // 3.2 specify the format OutputFormat format = OutputFormat. createPrettyPrint (); // sets the encoding format. setEncoding ("UTF-8"); XMLWriter writer = new XMLWriter (out, format); // 3.3 write the content writer. write (doc); // 3.4 close the resource writer. close ();}}
  
 

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