Export excel in SHH (using POI)

1. In struts. xml

<Action name = "exportexcelaction" class = "com. Ht. Action. Exam. examresultaction"> <result name = "success" type = "stream"> <! -- Type = "stream" indicates the binary file to be downloaded --> <Param name = "contenttype"> application/vnd. MS-Excel </param> <! -- Specify the file type --> <Param name = "contentdisposition"> attachment; filename = "grade_analysis.xls" </param> <! -- The attachment attribute is to be opened separately, rather than in the browser. The default value is inline. specify the name of the downloaded file --> <Param name = "inputname"> exportresult </param> <! -- Specifies the name of the method for downloading an object. Here, special attention must be given to the same method name as the method name in action --> </result> </Action>

 

 

2. In the action

Public inputstream getexportresult () throws unsupportedencodingexception {// The get method name must be consistent with struts. claid = java.net. urldecoder. decode (claid, "UTF-8"); // decode STR = java.net in order to solve the garbled problem of JS value passing. urldecoder. decode (STR, "UTF-8"); return this. resultservice. getinputstream (claid, STR );}

 

 

3. In Service

// Export the public inputstream getinputstream (string claid, string Str) in Excel; // This is a method for defining the input stream

 

 

4. At the service Implementation Layer

/** Process Excel export **/Public inputstream getinputstream (string claid, string Str) {// system. out. println ("class" + claid + "string" + Str); // process the passed string [] type = Str. split ("-"); int Len = type. length; // system. out. println ("array length:" + Len); hssfworkbook WB = new hssfworkbook (); // use poi to import a POI package, first, generate an hssfworkbook object hssfsheet sheet = WB. createsheet ("sheet1"); // create an Excel sheet. createrow (0); // create the first hssfcell cell = row. createcell (short) 0); // create the first cell. setencoding (hssfcell. encoding_utf_16); // set the encoding format for each cell. setcellvalue ("Serial Number"); For (INT I = 0; I <Len; I ++) {Cell = row. createcell (short) (I + 1); // create cells in sequence. setencoding (hssfcell. encoding_utf_16); // set the encoding format for each cell. setcellvalue (type [I]);}/* the header has been designed. ** The following is the data read from the database */string querystring = "from result as res where res. student. classes. claid = "+ claid; List <result> res = NULL; Res = resultdao. getlistbyhql (querystring); // store the expected score records to the for (INT I = 0; I <res. size (); I ++) {result = res. get (I); // get a record ROW = sheet. createrow (I + 1); // generate the following cell = row. createcell (short) 0); // the first cell. setencoding (hssfcell. encoding_utf_16); cell. setcellvalue (I + 1); For (int A = 0; A <Len; A ++) {// The following cells are displayed in sequence. // system. out. println ("who is now" + type [a]); cell = row. createcell (short) (a + 1); cell. setencoding (hssfcell. encoding_utf_16); If (type [A]. equals ("student ID") {Cell. setcellvalue (result. getstudent (). getstunum ();} else if (type [A]. equals ("examinee name") {Cell. setcellvalue (result. getstudent (). getstuname ();} else if (type [A]. equals ("examinee name") {Cell. setcellvalue (result. getstudent (). getstuname ();} else if (type [A]. equals ("examinee class") {Cell. setcellvalue (result. getstudent (). getclasses (). getclaname ();} else if (type [A]. equals ("gender") {Cell. setcellvalue (result. getstudent (). getstusex ();} else if (type [A]. equals ("Exam Score") {Cell. setcellvalue (result. getresscore ();} else if (type [A]. equals ("test time") {Cell. setcellvalue (result. getresbegin ();} else if (type [A]. equals ("Submit time") {Cell. setcellvalue (result. getresend ();} else if (type [A]. equals ("Exam time") {try {Cell. setcellvalue (gettimedifference (result. getresend (), result. getresbegin ();} catch (exception e) {e. printstacktrace () ;}}}/ ** the required Excel file is generated. * write another method to avoid temporary files, in the memory */bytearrayoutputstream OS = new bytearrayoutputstream (); try {WB. write (OS);} catch (ioexception e) {e. printstacktrace ();} byte [] content = OS. tobytearray (); inputstream is = new bytearrayinputstream (content); return is ;}

 

 

5. resultdao

　　

public List<Result> getListByHQL(String queryString);

 

 

6. DAO implementation Layer

public List<Result> getListByHQL(String queryString){   　　return getHibernateTemplate().find(queryString); }

 

 

7. resullt object class

　　

package com.ht.entity;/**  * Result entity. @author MyEclipse Persistence Tools */public class Result implements java.io.Serializable { // Fields private Integer resId;  private Student student;  private ClassTest classTest;  private String resBegin;  private String resEnd;  private String resScore; // Constructors /** default constructor */  public Result() {  } /** full constructor */  public Result(Student student, ClassTest classTest, String resBegin,    String resEnd, String resScore){  　　this.student = student;   　　this.classTest = classTest;   　　 this.resBegin = resBegin;   　　 this.resEnd = resEnd;   　　this.resScore = resScore;  } // Property accessors public Integer getResId() {   return this.resId;  } public void setResId(Integer resId) {   this.resId = resId;  } public Student getStudent() {   return this.student;  } public void setStudent(Student student) {   this.student = student;  } public ClassTest getClassTest() {   return this.classTest;  } public void setClassTest(ClassTest classTest) {   this.classTest = classTest;  } public String getResBegin() {   return this.resBegin;  } public void setResBegin(String resBegin) {   this.resBegin = resBegin;  } public String getResEnd() {   return this.resEnd;  } public void setResEnd(String resEnd) {   this.resEnd = resEnd;  } public String getResScore() {   return this.resScore;  } public void setResScore(String resScore) {   this.resScore = resScore;  }}

 

 

 

 

8. Presentation Layer

<HTML> 
 
 
6. JS is also used for passing values, which can be modified as needed.
JS:
// Export an Excel file. You cannot use Ajax function exportexcel (tagaction) {var claid = $ ("# claid "). val (); var input = $ ("input [name = 'std']"); // obtain all values first, and Judge var STR = "" Through loops ""; for (I = 0; I <input. length; I ++) {If (input [I]. checked) {STR = STR + input [I]. value + "-"; // connect the selected item to the background as a string} If (claid = "0") {alert ("select a class first! "); Return;} If (STR = NULL | STR =") {alert ("select the item to export first! "); Return;} // garbled, two encodeuri packages window. Location. href =" exportexcelaction. Action? Claid = "+ encodeuri (claid) +" & STR = "+ encodeuri (STR) + "";}