1 import java.io.*;
  2
  3 /**
  4  * @author jiashubing
  5  * @since 2019/5/22
  6  */
  7 public class DeleteLine {
  8     public static void main(String[] args) {
  9         String path = "C:\\Users\\jiashubing\\Desktop\\ttt\\workspace.xml";
 10         deleteLine(path);
 11     }
 12
 13     private static String deleteLine(String path) {
 14         int a = path.lastIndexOf('/');
 15         int b = path.lastIndexOf('\\');
 16         if (a < 0 && b < 0) {
 17             return "没有目录分隔符";
 18         }
 19
 20         //删除原来的备份文件
 21         String bakpath = path + ".bak";
 22         if (deleteFile(bakpath)) {
 23             return "删除原始的备份文件失败，备份文件为：" + bakpath;
 24         }
 25
 26         String bakpath2 = path + ".bak2";
 27         if (deleteFile(bakpath2)) {
 28             return "删除原始的临时备份文件失败，备份文件为：" + bakpath2;
 29         }
 30
 31         //创建临时备份文件
 32         File bakFile2 = new File(bakpath2);
 33         boolean nFlag = false;
 34         try {
 35             nFlag = bakFile2.createNewFile();
 36         } catch (IOException e) {
 37             return "创建临时备份文件失败，备份文件为：" + bakpath2 + "  错误信息为：" + e.getMessage();
 38         }
 39         if (!nFlag) {
 40             return "创建临时备份文件失败，备份文件为：" + bakpath2;
 41         }
 42
 43         String ans = getAns(path);
 44         if (ans == null) {
 45             return "读取并修改原始文件失败";
 46         }
 47
 48         if (!addNewFile(bakpath2, ans)) {
 49             return "将修改后的内容写入到新文件失败";
 50         }
 51
 52         File oldFile = new File(path);
 53         boolean mvFlag = oldFile.renameTo(new File(bakpath));
 54         if (!mvFlag) {
 55             return "将原始文件重命名成备份文件失败";
 56         }
 57
 58         boolean mvFlag2 = bakFile2.renameTo(new File(path));
 59         if (!mvFlag2) {
 60             return "将临时备份文件重命名成原始文件失败";
 61         }
 62
 63         return "执行成功";
 64     }
 65
 66     private static boolean deleteFile(String bakpath) {
 67         File bakFile = new File(bakpath);
 68         if (bakFile.exists() && bakFile.isFile()) {
 69             boolean delFlag = bakFile.delete();
 70             if (!delFlag) {
 71                 return true;
 72             }
 73         }
 74         return false;
 75     }
 76
 77     private static String getAns(String path) {
 78         File oldFile = new File(path);
 79         if (!oldFile.exists() || !oldFile.isFile()) {
 80             return null;
 81         }
 82
 83         StringBuilder ans = new StringBuilder();
 84         String encoding = "UTF-8";
 85         try (InputStreamReader read = new InputStreamReader(
 86                 new FileInputStream(oldFile), encoding);
 87              BufferedReader bufferedReader = new BufferedReader(read)) {
 88             String lineTxt = null;
 89             while ((lineTxt = bufferedReader.readLine()) != null) {
 90                 if (lineTxt.contains("name=\"x\"") || lineTxt.contains("name=\"y\"")) {
 91                     continue;
 92                 }
 93                 ans.append(lineTxt + "\n");
 94             }
 95         } catch (Exception e) {
 96             return null;
 97         }
 98
 99         return ans.toString();
100     }
101
102     private static boolean addNewFile(String path, String ans) {
103         File file = new File(path);
104
105         try (Writer out = new FileWriter(file)) {
106             out.write(ans);
107         } catch (IOException e) {
108             return false;
109         }
110
111         return true;
112     }
113 }