Java struts2 getting started-two ways to download files

I. about File Download: the core idea of File Download is to copy an object from one place to another. 1. traditional Method: Add a large number of servlet api operations to the Action. the advantage is good understanding, and the disadvantage is high coupling. 2. stream method: Use the stream interceptor in struts2 for operation 2. example: I use maven and paste the pom. xml: Copy Code <project xmlns = "http://maven.apache.org/POM/4.0.0" xmlns: xsi = "http://www.w3.org/2001/XMLSchema-instance" xsi: schemaLocation = "http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion> 4.0.0 </modelVersion> <groupId> com. amos </groupId> <artifactId> struts2_learn </artifactId> <packaging> war </packaging> <Version> 0.0.1-SNAPSHOT </version> <name> struts2_learn Maven Webapp </name> <url> http://maven.apache.org </url> <dependencies> <dependency> <groupId> junit </ groupId> <artifactId> junit </artifactId> <version> 4.11 </version> <scope> test </scope> </dependency> <groupId> org. apache. struts </groupId> <artifactId> struts2-core </artifactId> <version> 2.3.16 </version> </dependency> <groupId> Org. apache. commons </groupId> <artifactId> commons-io </artifactId> <version> 1.3.2 </version> </dependency> <groupId> jstl </groupId> <artifactId> jstl </artifactId> <version> 1.1.2 </version> <scope> provided </scope> </dependency> <groupId> taglibs </groupId> <artifactId> standard </artifactId> <version> 1.1.2 </version> </dependency> </dependencies> <build> <finalName> struts2_learn </fi NalName> </build> </project> copy Code 1. downloadAction. java copy code package download; import java. io. fileInputStream; import java. io. inputStream; import java. io. outputStream; import java. io. unsupportedEncodingException; import java.net. URLEncoder; import javax. servlet. servletContext; import javax. servlet. http. httpServletResponse; import org. apache. struts2.ServletActionContext; import com. opensymphony. xw Ork2.ActionSupport;/*** @ ClassName: DownloadAction * @ Description: File Download * @ author: amosli * @ email: amosli@infomorrow.com * @ date Feb 13,201 4 1:22:23 AM */public class DownloadAction extends ActionSupport {private static final long serialVersionUID =-5609061774544252181l; private String fileName; // file name public void setFileName (String fileName) {if (ServletActionContext. getRequest (). getMethod (). equ Als ("GET") {try {byte [] bytes = fileName. getBytes ("ISO8859-1"); // process the Chinese character submitted by the get method, converting the encoding from the ISO8859-1 to UTF-8 fileName = new String (bytes, "UTF-8 ");} catch (UnsupportedEncodingException e) {e. printStackTrace () ;}} this. fileName = fileName;} // download public String execute () throws Exception {// 1. traditional download method // obtain the HttpServletResponse object HttpServletResponse response = ServletActionContext. getResponse (); // get The ServletContext object ServletContext context = ServletActionContext. getServletContext (); // notify the browser to open the file response as a download. setHeader ("content-disposition", "attachment; filename =" + URLEncoder. encode (fileName, "UTF-8"); // obtain the root directory String realPath = context. getRealPath ("/WEB-INF/download"); // construct the subnode input stream InputStream is = new FileInputStream (realPath + "/" + fileName ); // construct the output stream OutputStream OS = response. g EtOutputStream (); byte [] B = new byte [1024]; int len = 0; while (len = is. read (B)> 0) {OS. write (B, 0, len);} is. close (); OS. close (); return SUCCESS ;}} copy the code download. jsp copy the Code <% @ page language = "java" contentType = "text/html; charset = UTF-8" pageEncoding = "UTF-8" %> <% @ taglib uri = 'HTTP: // java.sun.com/jsp/jstl/core' prefix = "c" %> <! DOCTYPE html PUBLIC "-// W3C // dtd html 4.01 Transitional // EN" "http://www.w3.org/TR/html4/loose.dtd">