获取表单传输的所有数据，包括所有文本字段和所有文件字段

Posted 2021-03-12 mahoshojo

package net.add1s.util;

import cn.hutool.core.io.resource.WebAppResource;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.commons.io.IOUtils;
import javax.servlet.http.HttpServletRequest;
import java.io.File;
import java.io.FileOutputStream;
import java.util.*;

/**
 * @author github.com@lalafaye
 */
public class UploadUtils {

    /**
     * 所有文本字段
     */
    public static final String TEXT_FIELDS = "text_fields";

    /**
     * 所有文件字段
     */
    public static final String FILE_FIELDS = "file_fields";

    /**
     * 上传大小限制(2M)
     */
    private static long maxUploadSize = 2097152;

    /**
     * 文件保存目录路径
     */
    private static String savePath = "";

    /**
     * 文件上传保存文件夹名
     */
    private static String basePath = "upload";

    public static boolean upload(HttpServletRequest request) {
        List<FileItem> fileList = (List<FileItem>) getAllItems(request).get(FILE_FIELDS);
        System.out.println(fileList.size());
        if (fileList != null) {
            for (FileItem file : fileList) {
                saveFile(file);
            }
        }
        return false;
    }

    /**
     * 获取表单中的所有文本和文件字段
     *
     * @param request
     * @return map
     */
    public static Map getAllItems(HttpServletRequest request) {

        // savePath = new WebAppResource("\" + basePath).toString();

        savePath = "D:\IntelliJ_IDEA_2018_3_1\IDEA_workspace\Confession\src\main\webapp\upload";

        // 存储表单字段和非表单字段
        Map<String, Object> map = new HashMap<>(2);

        // 第一步：判断request
        boolean isMultipart = ServletFileUpload.isMultipartContent(request);

        // 第二步：解析request
        if (isMultipart) {
            // Create a factory for disk-based file items
            DiskFileItemFactory factory = new DiskFileItemFactory();

            // 阀值（10M）,超过这个值才会写到临时目录,否则在内存中
            factory.setSizeThreshold(1024 * 1024 * 10);
            factory.setRepository(new File(savePath + "\temp"));

            // Create a new file upload handler
            ServletFileUpload upload = new ServletFileUpload(factory);

            upload.setHeaderEncoding("UTF-8");

            // 最大上传限制
            upload.setSizeMax(maxUploadSize);

            /* FileItem */
            List<FileItem> items = null;
            // Parse the request
            try {
                items = upload.parseRequest(request);
            } catch (FileUploadException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

            // 第3步：处理uploaded items
            if (items != null && items.size() > 0) {
                Iterator<FileItem> iter = items.iterator();
                // 文件域对象List
                List<FileItem> fileFieldsList = new ArrayList<>();
                // 表单字段Map
                Map<String, String> textFieldsMap = new HashMap<>();
                while (iter.hasNext()) {
                    FileItem item = iter.next();
                    // 处理所有表单元素和文件域表单元素
                    if (item.isFormField()) { // 表单元素
                        String name = item.getFieldName();
                        String value = item.getString();
                        textFieldsMap.put(name, value);
                    } else { // 文件域表单元素
                        fileFieldsList.add(item);
                    }
                }
                map.put(FILE_FIELDS, fileFieldsList);
                map.put(TEXT_FIELDS, textFieldsMap);
            }
        }
        return map;
    }

    public static AjaxResult saveFile(FileItem item) {

        System.out.println(savePath);

        // 文件名
        String fileName = item.getName();
        // 后缀
        String fileExt = fileName.substring(fileName.lastIndexOf(".") + 1).toLowerCase();

        // 检查文件大小
        if (item.getSize() > maxUploadSize) {
            // TODO
            return AjaxResult.me().setSuccess(false).setMsg("文件太大，上传失败");
        } else {
            String newFileName = UUID.randomUUID().toString() + "." + fileExt;
            try {
                IOUtils.copy(item.getInputStream(), new FileOutputStream(new File(savePath, newFileName)));
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        System.gc();
        return AjaxResult.me();
    }
}

package net.add1s.util;

/**
 * Ajax请求响应对象的类
 *
 * @author github.com@lalafaye
 */
public class AjaxResult {

    private boolean success = true;

    private String msg = "Successful operation!";

    /**
     * 返回到前台对象
     */
    private Object resultObj;

    public boolean isSuccess() {
        return success;
    }

    public AjaxResult setSuccess(boolean success) {
        this.success = success;
        return this;
    }

    public String getMsg() {
        return msg;
    }

    public AjaxResult setMsg(String msg) {
        this.msg = msg;
        return this;
    }

    public Object getResultObj() {
        return resultObj;
    }

    public AjaxResult setResultObj(Object resultObj) {
        this.resultObj = resultObj;
        return this;
    }

    /**
     * AjaxResult.me() 成功
     * AjaxResult.me().setMsg() 成功
     * AjaxResult.me().setSuccess(false).setMsg("失败");
     *
     * @return
     */
    public static AjaxResult me() {
        return new AjaxResult();
    }
}