diff --git a/src/edu/tyut/selaba2/student/DAO/impl/DAO.java b/src/edu/tyut/selaba2/student/DAO/impl/DAO.java
index 7a6a583e60267be5c7920ad805d3fc3b72fb2c46..43e6abc7c049e09d9da67c3d03cc8191644b4d6b 100644
--- a/src/edu/tyut/selaba2/student/DAO/impl/DAO.java
+++ b/src/edu/tyut/selaba2/student/DAO/impl/DAO.java
@@ -1,16 +1,44 @@
 package edu.tyut.selaba2.student.DAO.impl;
 
 import edu.tyut.selaba2.student.DAO.BaseDAO;
+import edu.tyut.selaba2.student.entity.Student;
 import edu.tyut.selaba2.student.entity.StudentMap;
+import edu.tyut.selaba2.student.util.FileUtil;
+import edu.tyut.selaba2.student.util.JSONUtil;
+
+import java.io.FileWriter;
+import java.io.IOException;
 
 public class DAO implements BaseDAO {
     @Override
     public StudentMap getStudentMap(String simpleName) {
-        return null;
+        StudentMap sm = null;
+        try {
+            String s = FileUtil.readInFile(simpleName);
+             sm = JSONUtil.JSON2Entity(s,StudentMap.class);
+            return sm;
+        } catch (IOException e) {
+            e.printStackTrace();
+            return sm;
+        }
+
     }
 
     @Override
     public boolean saveData(StudentMap studentMap, String simpleName) {
-        return false;
+        String s = JSONUtil.entity2JSON(studentMap);
+        try {
+            FileWriter fileWriter = new FileWriter("simpleName");
+            fileWriter.write(s);
+            fileWriter.flush();
+            return true;
+        } catch (IOException e) {
+            e.printStackTrace();
+            return false;
+        }
     }
+
+
+
+
 }
diff --git a/src/edu/tyut/selaba2/student/repository/impl/StudentRepositoryImpl.java b/src/edu/tyut/selaba2/student/repository/impl/StudentRepositoryImpl.java
index cb58c8627e07c6d09f969779be4c08e5cc3910f3..d174564b9dcfdf4c16eb9877abf6db4ec50c7f72 100644
--- a/src/edu/tyut/selaba2/student/repository/impl/StudentRepositoryImpl.java
+++ b/src/edu/tyut/selaba2/student/repository/impl/StudentRepositoryImpl.java
@@ -1,29 +1,70 @@
 package edu.tyut.selaba2.student.repository.impl;
 
+import edu.tyut.selaba2.student.DAO.impl.DAO;
 import edu.tyut.selaba2.student.entity.Student;
+import edu.tyut.selaba2.student.entity.StudentMap;
 import edu.tyut.selaba2.student.repository.StudentRepository;
+//import jdk.internal.icu.text.UnicodeSet;
 
-import java.util.List;
+import java.util.*;
+import java.util.stream.Collectors;
 
 public class StudentRepositoryImpl implements StudentRepository {
+
     @Override
     public void save(Student student) {
+        DAO database=new DAO();
+        StudentMap studentMap = database.getStudentMap("student.txt");
+        if(studentMap.containsKey(student.getUid())){
+            update(student);
+        }else{
+            studentMap.put(student.getUid(),student);
+            database.saveData(studentMap,"student.txt");
 
+        }
     }
 
+
     @Override
     public boolean insert(Student student) {
-        return false;
+        DAO database=new DAO();
+        StudentMap studentMap = database.getStudentMap("student.txt");
+        if(studentMap.containsKey(student.getUid())){
+            return false;
+        }else{
+            studentMap.put(student.getUid(),student);
+            database.saveData(studentMap,"student.txt");
+            return true;
+        }
+
     }
 
     @Override
     public boolean delete(Long uid) {
-        return false;
+        DAO database=new DAO();
+        StudentMap studentMap = database.getStudentMap("student.txt");
+        if(studentMap.containsKey(uid)){
+            studentMap.remove(uid);
+            database.saveData(studentMap,"student.txt");
+//            if(studentMap.containsKey(uid)==false){
+            return true;
+//            }
+        }else{
+            return false;
+        }
+
     }
 
     @Override
     public boolean update(Student student) {
-        return false;
+        DAO database=new DAO();
+        StudentMap studentMap = database.getStudentMap("student.txt");
+        if(studentMap.containsKey(student.getUid())){
+            studentMap.put(student.getUid(),student);
+            return true;
+        }else{
+            return false;
+        }
     }
 
     @Override
@@ -33,7 +74,26 @@ public class StudentRepositoryImpl implements StudentRepository {
 
     @Override
     public List<Student> findStudentByExample(Student student) {
-        return null;
+        DAO database=new DAO();
+        StudentMap studentMap = database.getStudentMap("student.txt");
+        Collection<Student> studentCollection = studentMap.values();
+        List<Student> selectedStudentList = studentCollection.stream().filter(e ->
+                (e.getUid().equals(student.getUid() == null ? e.getUid() : student.getUid())
+                        && e.getName().equals(student.getName() == null ? e.getName() : student.getName())
+                        && e.getClassNumber().equals(student.getClassNumber() == 0 ? e.getClassNumber() : student.getClassNumber())
+                        && e.getDepartment().equals(student.getDepartment() == null ? e.getDepartment() : student.getDepartment())
+                        && e.getSex().equals(student.getSex() == null ? e.getSex() : student.getSex())
+                        && e.getAge().equals(student.getAge() == null ? e.getAge() : student.getAge())
+                )
+        ).collect(Collectors.toList());
+        if(selectedStudentList.size()!=0){
+            return selectedStudentList;
+        }else{
+            List<Student> nullStudentList=new ArrayList<>();
+            return nullStudentList;
+        }
+
+
     }
 
     @Override
@@ -41,3 +101,4 @@ public class StudentRepositoryImpl implements StudentRepository {
         return null;
     }
 }
+
diff --git a/src/edu/tyut/selaba2/student/util/FileUtil.java b/src/edu/tyut/selaba2/student/util/FileUtil.java
index 52c29954c581805651dd96bc075dc41d0931385f..abb31273425217ed057fcdfc37d21caf4f5013a8 100644
--- a/src/edu/tyut/selaba2/student/util/FileUtil.java
+++ b/src/edu/tyut/selaba2/student/util/FileUtil.java
@@ -18,7 +18,14 @@ public class FileUtil {
      * @return true     如果写入成功
      *         false    如果写入失败
      */
-    public static boolean writeInFile(String content,String simpleName){
+    public static boolean writeInFile(String content,String simpleName) throws IOException {
+
+        String sourcePath = "data/"+ simpleName.toLowerCase() + ".txt";
+        File sourceFile = new File(sourcePath);
+        byte[] a=content.getBytes("UTF-8");
+        FileOutputStream o=new FileOutputStream(sourceFile);
+        o.write(a);
+        o.close();
         return false;
     }
 
@@ -31,7 +38,17 @@ public class FileUtil {
      * @return String 如果成功，返回数据内容
      *          null 如果失败返回，null
      */
-    public static String readInFile(String simpleName){
+    public static String readInFile(String simpleName) throws IOException {
+        String sourcePath = "data/"+ simpleName.toLowerCase() + ".txt";
+        File sourceFile = new File(sourcePath);
+        FileInputStream o=new FileInputStream(sourceFile);
+        InputStreamReader fr=new InputStreamReader(o,"gbk");
+        BufferedReader br=new BufferedReader(fr);
+        String s=new String();
+        int i=0;
+        if ((s=br.readLine())!=null){
+            return s;
+        }
         return null;
     }