Spring Boot 导出Word文档（二）结束篇

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书接上文

该怎么生成导出字节流呢

首先是获取模板文件 然后创建一个文件对象 和一个输入字节流 和一个 输出字节流对象 然后调用上文的createDoc()方法来生成一个文件 然后通过FileInputStream()方法来生成一个输入字节流 然后再把输入字节流的内容给转到输出字节流里来让浏览器下载 具体就是这么一个流程 有不懂的看几遍代码应该就清晰了

   public static void exportMillCertificateWord(HttpServletRequest request, HttpServletResponse response, Map map, String title, String ftlFile) throws IOException {
        Template freemarkerTemplate = configuration.getTemplate(ftlFile);
        File file = null;
        InputStream fin = null;
        ServletOutputStream out = null;
        try {

            // 调用工具类的createDoc方法生成Word文档
            file = createDoc(map, freemarkerTemplate);
            fin = new FileInputStream(file);

            response.setCharacterEncoding("utf-8");
            response.setContentType("application/msword");
            // 设置浏览器以下载的方式处理该文件名
            String fileName = title  + ".doc";
            response.setHeader("Content-Disposition", "attachment;filename="
                    .concat(String.valueOf(URLEncoder.encode(fileName, "UTF-8"))));

            out = response.getOutputStream();
            byte[] buffer = new byte[512];  // 缓冲区
            int bytesToRead = -1;
            // 通过循环将读入的Word文件的内容输出到浏览器中
            while ((bytesToRead = fin.read(buffer)) != -1) {
                out.write(buffer, 0, bytesToRead);
            }
        } finally {
            if (fin != null) fin.close();
            if (out != null) out.close();
            if (file != null) file.delete(); // 删除临时文件
        }
    }

而整个工具类的全文如下

package com.zhong.share.work.control.JudeController;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.util.Map;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import freemarker.template.Configuration;
import freemarker.template.Template;

public class WordUtils {

    private static Configuration configuration = null;
        //classLoader.getResource()只能获取相对路径的资源
//     private static  String templateFolder = WordUtils.class.getClassLoader().getResource("/teacherPlan.ftl").getPath();
    private static  String templateFolder = "F://controlleclass//src//main//resources//people";
        //class.getResource()可以获取绝对路径和相对路径
//        private static String templateFolder = WordUtils.class.getResource("/teacherPlan").getPath();


    static {
        configuration = new Configuration();
        configuration.setDefaultEncoding("utf-8");
        try {
        	templateFolder = URLDecoder.decode(templateFolder, "UTF-8");
        	System.out.println(templateFolder);
            configuration.setDirectoryForTemplateLoading(new File(templateFolder));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private WordUtils() {
        throw new AssertionError();
    }

    public static void exportMillCertificateWord(HttpServletRequest request, HttpServletResponse response, Map map, String title, String ftlFile) throws IOException {
        Template freemarkerTemplate = configuration.getTemplate(ftlFile);
        File file = null;
        InputStream fin = null;
        ServletOutputStream out = null;
        try {

            // 调用工具类的createDoc方法生成Word文档
            file = createDoc(map, freemarkerTemplate);
            fin = new FileInputStream(file);

            response.setCharacterEncoding("utf-8");
            response.setContentType("application/msword");
            // 设置浏览器以下载的方式处理该文件名
            String fileName = title  + ".doc";
            response.setHeader("Content-Disposition", "attachment;filename="
                    .concat(String.valueOf(URLEncoder.encode(fileName, "UTF-8"))));

            out = response.getOutputStream();
            byte[] buffer = new byte[512];  // 缓冲区
            int bytesToRead = -1;
            // 通过循环将读入的Word文件的内容输出到浏览器中
            while ((bytesToRead = fin.read(buffer)) != -1) {
                out.write(buffer, 0, bytesToRead);
            }
        } finally {
            if (fin != null) fin.close();
            if (out != null) out.close();
            if (file != null) file.delete(); // 删除临时文件
        }
    }

    private static File createDoc(Map<?, ?> dataMap, Template template) {
        String name = "sellPlan.doc";
        File f = new File(name);
        Template t = template;
        try {
            // 这个地方不能使用FileWriter因为需要指定编码类型否则生成的Word文档会因为有无法识别的编码而无法打开
            Writer w = new OutputStreamWriter(new FileOutputStream(f), "utf-8");
            t.process(dataMap, w);
            w.close();
        } catch (Exception ex) {
            ex.printStackTrace();
            throw new RuntimeException(ex);
        }
        return f;
    }
}

而怎么在control类里调用呢 则把数据放到map里 然后输出

      //下载违规人员表
    @GetMapping("/export")
    public  void exportSellPlan(HttpServletRequest request, HttpServletResponse response){

        User user = new User();

        List<User> list = new ArrayList<>();
        list = userService.JudedPeople();

        String prestr = "";
        for (int i = 0; i < list.size(); i++) {
            User u = list.get(i);
            String value = u.getUsername();
            if (i == list.size() - 1) {// 拼接时，不包括最后一个&字符
                prestr = prestr + "   " + value;
            }
            else {
                prestr = prestr + "   " + value + "   ";
            }

        }

            Map<String, Object> map = new HashMap<String, Object>();
            map.put("peopleid", prestr);
            try {
                WordUtils.exportMillCertificateWord(request, response, map, "违规人员表", "people.ftl");
            } catch (IOException e) {
                e.printStackTrace();}

        }