JSON格式串以CSV格式保存

来源：互联网发布：子账号在淘宝哪里登陆编辑：程序博客网时间：2024/05/16 14:35
在报表项目开发过程中，UI端显示的数据用户想通过界面的”下载“按钮保存下来，而数据已经以JSON格式得到了，这是只需要把json格式的文件转化为excel，怎么转化，开源的有org.json.CDL,但这个东东的缺点是转化后就不能UI上的顺序保持一致，为此专门改写了网上的代码，见
List exportData = getKeyValFromJson(account_rep);
LinkedHashMap map = getKeyFromJson(account_rep);
import java.io.BufferedWriter;import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import java.io.OutputStreamWriter;import java.net.URLEncoder;import java.util.ArrayList;import java.util.Iterator;import java.util.LinkedHashMap;import java.util.List;import java.util.Map; import javax.servlet.http.HttpServletResponse; import org.apache.commons.beanutils.BeanUtils; /** * 文件操作 */public class CSVUtils {   /**   * 生成为CVS文件    * @param exportData   *       源数据List   * @param map   *       csv文件的列表头map   * @param outPutPath   *       文件路径   * @param fileName   *       文件名称   * @return   */  @SuppressWarnings("rawtypes")  public static File createCSVFile(List exportData, LinkedHashMap map, String outPutPath,                   String fileName,String encoding) {    File csvFile = null;    BufferedWriter csvFileOutputStream = null;    try {      File file = new File(outPutPath);      if (!file.exists()) {        file.mkdir();      }      //定义文件名格式并创建      csvFile = File.createTempFile(fileName, ".csv", new File(outPutPath));      System.out.println("csvFile：" + csvFile);      // UTF-8使正确读取分隔符","       csvFileOutputStream = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(        csvFile), encoding), 1024);      System.out.println("csvFileOutputStream：" + csvFileOutputStream);      // 写入文件头部       for (Iterator propertyIterator = map.entrySet().iterator(); propertyIterator.hasNext();) {        java.util.Map.Entry propertyEntry = (java.util.Map.Entry) propertyIterator.next();        csvFileOutputStream          .write((String) propertyEntry.getValue() != null ? (String) propertyEntry            .getValue() : "");        if (propertyIterator.hasNext()) {          csvFileOutputStream.write(",");        }      }      csvFileOutputStream.newLine();      // 写入文件内容       for (Iterator iterator = exportData.iterator(); iterator.hasNext();) {        Object row = (Object) iterator.next();        for (Iterator propertyIterator = map.entrySet().iterator(); propertyIterator          .hasNext();) {          java.util.Map.Entry propertyEntry = (java.util.Map.Entry) propertyIterator            .next();          csvFileOutputStream.write((String) BeanUtils.getProperty(row,            (String) propertyEntry.getKey()));          if (propertyIterator.hasNext()) {            csvFileOutputStream.write(",");          }        }        if (iterator.hasNext()) {          csvFileOutputStream.newLine();        }      }      csvFileOutputStream.flush();    } catch (Exception e) {      e.printStackTrace();    } finally {      try {        csvFileOutputStream.close();      } catch (IOException e) {        e.printStackTrace();      }    }    return csvFile;  }   /**   * 下载文件   * @param response   * @param csvFilePath   *       文件路径   * @param fileName   *       文件名称   * @throws IOException   */  public static void exportFile(HttpServletResponse response, String csvFilePath, String fileName)                                                  throws IOException {    response.setContentType("application/csv;charset=UTF-8");    response.setHeader("Content-Disposition",      "attachment; filename=" + URLEncoder.encode(fileName, "UTF-8"));     InputStream in = null;    try {      in = new FileInputStream(csvFilePath);      int len = 0;      byte[] buffer = new byte[1024];      response.setCharacterEncoding("UTF-8");      OutputStream out = response.getOutputStream();      while ((len = in.read(buffer)) > 0) {        out.write(new byte[] { (byte) 0xEF, (byte) 0xBB, (byte) 0xBF });        out.write(buffer, 0, len);      }    } catch (FileNotFoundException e) {      System.out.println(e);    } finally {      if (in != null) {        try {          in.close();        } catch (Exception e) {          throw new RuntimeException(e);        }      }    }  }      /**   * 下载文件   * @param response   * @param csvFilePath   *       文件路径   * @param fileName   *       文件名称   * @throws IOException   */  public static void get(HttpServletResponse response, String csvFilePath, String fileName)                                                  throws IOException {    response.setContentType("application/csv;charset=UTF-8");    response.setHeader("Content-Disposition",      "attachment; filename=" + URLEncoder.encode(fileName, "UTF-8"));     InputStream in = null;    try {      in = new FileInputStream(csvFilePath);      int len = 0;      byte[] buffer = new byte[1024];      response.setCharacterEncoding("UTF-8");      OutputStream out = response.getOutputStream();      while ((len = in.read(buffer)) > 0) {        out.write(new byte[] { (byte) 0xEF, (byte) 0xBB, (byte) 0xBF });        out.write(buffer, 0, len);      }    } catch (FileNotFoundException e) {      System.out.println(e);    } finally {      if (in != null) {        try {          in.close();        } catch (Exception e) {          throw new RuntimeException(e);        }      }    }  }    /**   * 删除该目录filePath下的所有文件   * @param filePath   *      文件目录路径   */  public static void deleteFiles(String filePath) {    File file = new File(filePath);    if (file.exists()) {      File[] files = file.listFiles();      for (int i = 0; i < files.length; i++) {        if (files[i].isFile()) {          files[i].delete();        }      }    }  }   /**   * 删除单个文件   * @param filePath   *     文件目录路径   * @param fileName   *     文件名称   */  public static void deleteFile(String filePath, String fileName) {    File file = new File(filePath);    if (file.exists()) {      File[] files = file.listFiles();      for (int i = 0; i < files.length; i++) {        if (files[i].isFile()) {          if (files[i].getName().equals(fileName)) {            files[i].delete();            return;          }        }      }    }  }   /**i   * 返回数组里面存放的是每条item的key-value   * @param sjoin   */   public static List getKeyValFromJson(String json){  if(json==null || "".endsWith(json)){return null;}  List exportData = new ArrayList<Map>();   int lenOfJson = json.length();  int itemEndIndex = 0;  String item="";  //[{"date":"2016-08-24","campaign":"铁弯头 额外","group_name":"cese"}]  for(int index= 0; index < lenOfJson; index++){  if(json.charAt(index)=='[') {  System.out.println("开始解析JSON");  }    if(json.charAt(index)=='{') {//unitl next item  System.out.println("开始解析一条item");  Map row = new LinkedHashMap<String, String>();  index++;  while(json.charAt(index)!='}'){  index=json.indexOf("\"",index);//direct into '"'  int index_keyend=json.indexOf("\":\"",index);//get key的endIndex(不计)  String key = json.substring(index+1,index_keyend);    index = json.indexOf("\"",index_keyend+3);// index  String value = json.substring(index_keyend+3, index);    value.replaceAll(",", "");  System.out.println(key+":"+value);  row.put(key, value);  //"," OR "}" after value  index+=1;  if(json.charAt(index)=='}'){  break;  }  }  System.out.println("结束解析一条item");  exportData.add(row);  }     if(json.charAt(index)==']') { System.out.println("结束解析JSON");     }    }        return exportData;  }    /**i   * 返回数组里面存放的是每条item的key-key   * @param sjoin   */   public static LinkedHashMap getKeyFromJson(String json){  if(json==null || "".endsWith(json)){return null;}  LinkedHashMap row = new LinkedHashMap<String, String>();  int lenOfJson = json.length();  String item="";//[{"date":"2016-08-24","campaign":"铁弯头 额外","group_name":"cese"}]  for(int index= 0; index < lenOfJson; index++){  if(json.charAt(index)=='[') {  System.out.println("开始解析JSON");  }    if(json.charAt(index)=='{') {//unitl next item  System.out.println("开始解析一条item");  index++;  while(json.charAt(index)!='}'){  index=json.indexOf("\"",index);//direct into '"'  int index_keyend=json.indexOf("\":\"",index);//get key的endIndex(不计)  String key = json.substring(index+1,index_keyend);    index = json.indexOf("\"",index_keyend+3);// index  String value = json.substring(index_keyend+3, index);    value =value.replaceAll(",", "");  System.out.println(key+":"+value);  row.put(key, key);    //"," OR "}" after value  index+=1;  if(json.charAt(index)=='}'){  break;  }  }    System.out.println("结束解析一条item");  }if(row.size()>0){break;}   }  return row;  }  /**   * 测试数据   * @param args   */  @SuppressWarnings({ "rawtypes", "unchecked" })  public static void main(String[] args) {  String account_rep = "";  List exportData = getKeyValFromJson(account_rep);  LinkedHashMap map = getKeyFromJson(account_rep);    /*List exportData = new ArrayList<Map>();    Map row1 = new LinkedHashMap<String, String>();    row1.put("1", "11");    row1.put("2", "12");    row1.put("3", "13");    row1.put("4", "14");    exportData.add(row1);    row1 = new LinkedHashMap<String, String>();    row1.put("1", "21");    row1.put("2", "22");    row1.put("3", "23");    row1.put("4", "24");    exportData.add(row1);    LinkedHashMap map = new LinkedHashMap();    map.put("1", "first");    map.put("2", "second");    map.put("3", "third");    map.put("4", "fourth");*/     String path = "c:/export/";    String fileName = "文件导出";    File file = CSVUtils.createCSVFile(exportData, map, path, fileName,"GB18030");    String fileName2 = file.getName();    System.out.println("文件名称：" + fileName2);  }}
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