Refactor

README.md

@@ -90,7 +90,7 @@ Refer to the file in this project, update the following files accordingly:
 - [src/main/resources/mybatis/mybatis-config.xml](src/main/resources/mybatis/mybatis-config.xml)
 - [src/main/resources/application.properties](src/main/resources/application.properties)
 - [src/main/resources/mapper/mainapp.xml](src/main/resources/mapper/mainapp.xml)
-- [src/main/java/com/badbuta/learnspringbootrestfulsqlite/ApiController.java](src/main/java/com/badbuta/learnspringbootrestfulsqlite/ApiController.java)
+- [src/main/java/com/example/demo/ApiController.java](src/main/java/com/example/demo/ApiController.java)
 
 # Init the database and insert sample data
 
@@ -111,6 +111,6 @@ To start this Spring Boot Application:
 1. Resolve WARN "MyBatis: No MyBatis mapper was found in '[xx.mapper]' package. Please check your configuration."
 1. Why `application.properties` - `spring.datasource.url` is requried even the mybatis config exist
     1. what should be the correct value? `jdbc:sqlite:data` or  `jdbc:sqlite:data:abc` ok ,but `jdbc:sqlite` not ok.
-1. In `src/main/java/com/badbuta/learnspringbootrestfulsqlite/ApiController.java`
+1. In `src/main/java/com/example/demo/ApiController.java`
     1. See the TODO
     1. Rewrite the controller code better

pom.xml

@@ -1,15 +1,16 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<parent>
 		<groupId>org.springframework.boot</groupId>
 		<artifactId>spring-boot-starter-parent</artifactId>
 		<version>3.2.0</version>
-		<relativePath/> <!-- lookup parent from repository -->
+		<relativePath/>
+		<!-- lookup parent from repository -->
 	</parent>
-	<groupId>com.badbuta</groupId>
-	<artifactId>learnspringbootrestfulsqlite</artifactId>
+	<groupId>com.example</groupId>
+	<artifactId>demo</artifactId>
 	<version>0.0.1-SNAPSHOT</version>
 	<name>Project for learning Spring Boot, RESTful API, and SQLite</name>
 	<description>This is a self-learing project for Spring Boot for RESTful API with SQLite database</description>
@@ -17,20 +18,17 @@
 		<java.version>17</java.version>
 	</properties>
 	<dependencies>
-
+		<dependency>
+			<groupId>org.wisdom-framework</groupId>
+			<artifactId>sqlite-jdbc</artifactId>
+			<version>3.8.7_1</version>
+			<scope>runtime</scope>
+		</dependency>
 		<dependency>
 			<groupId>com.google.code.gson</groupId>
 			<artifactId>gson</artifactId>
 			<version>2.10.1</version>
 		</dependency>
-
-
-		<dependency>
-			<groupId>org.xerial</groupId>
-			<artifactId>sqlite-jdbc</artifactId>
-			<version>3.44.1.0</version>
-		</dependency>
-
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-web</artifactId>
@@ -40,7 +38,6 @@
 			<artifactId>mybatis-spring-boot-starter</artifactId>
 			<version>3.0.3</version>
 		</dependency>
-
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-devtools</artifactId>

src/main/java/com/badbuta/learnspringbootrestfulsqlite/ApiController.java

@@ -1,84 +0,0 @@
-package com.badbuta.learnspringbootrestfulsqlite;
-
-import org.springframework.web.bind.annotation.RestController;
-
-import com.badbuta.learnspringbootrestfulsqlite.entities.User;
-import com.google.gson.Gson;
-
-import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.bind.annotation.RequestMethod;
-import org.springframework.web.bind.annotation.ResponseBody;
-
-import java.io.IOException;
-import java.util.List;
-import java.io.Reader;
-
-import org.apache.ibatis.io.Resources;
-import org.apache.ibatis.session.SqlSession;
-import org.apache.ibatis.session.SqlSessionFactory;
-import org.apache.ibatis.session.SqlSessionFactoryBuilder;
-import org.springframework.beans.factory.annotation.Value;
-import org.springframework.web.bind.annotation.CrossOrigin;
-import org.springframework.web.bind.annotation.GetMapping;
-
-/**
- * The RESTful API Controller Class
- * The URL for this API Controller is '/api/v1'
- * 
- * NOTE: By adding @CrossOrigin, Swagger preview can work perfectly.
- * 
- */
-@RestController
-@CrossOrigin
-@RequestMapping(value = "/api/v1")
-public class ApiController {
-
-    @Value("${mybatis.config-location}")
-    private String myBatisConfigLocation;
-
-    /**
-     * API Endpoint = /api (or /api/)
-     * 
-     * @return Simple text
-     */
-    @RequestMapping(value = { "", "/" }, method = RequestMethod.GET)
-    @ResponseBody
-    public String getRoot() {
-        // TODO: it is not a good practice and should return formatted JSON object
-        return "This is API root";
-    }
-
-    // @GetMapping("/test")
-    // public String getTest(@RequestParam(name = "a", required = false) String
-    // valA) {
-    // return "GET /test, param: a=" + valA;
-    // }
-
-    @GetMapping("fix")
-    public String getUsers() {
-        Gson gson = new Gson();
-
-        String myBatisConfigPath = myBatisConfigLocation.split(":")[1];
-
-        try (Reader in = Resources.getResourceAsReader(myBatisConfigPath)) {
-            // Create SQL Session Factory from mybatis config
-            SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(in);
-
-            // Create session
-            SqlSession session = factory.openSession();
-
-            // Select users
-            List<User> result = session
-                    .selectList("com.badbuta.learnspringbootrestfulsqlite.mapper.UserMapper.getUsers");
-
-            return gson.toJson(result);
-
-        } catch (IOException e) {
-            // If exception, return the exception object in JSON
-            // TODO: it is not a good practice and should return formatted error object
-            System.err.println(e);
-            return gson.toJson(e);
-        }
-
-    }
-}

src/main/java/com/badbuta/learnspringbootrestfulsqlite/UserController.java

@@ -1,58 +0,0 @@
-package com.badbuta.learnspringbootrestfulsqlite;
-
-import org.springframework.web.bind.annotation.RestController;
-
-import com.badbuta.learnspringbootrestfulsqlite.entities.User;
-import com.badbuta.learnspringbootrestfulsqlite.services.UserService;
-import org.springframework.web.bind.annotation.RequestMapping;
-import java.util.List;
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.web.bind.annotation.CrossOrigin;
-import org.springframework.web.bind.annotation.GetMapping;
-import org.springframework.web.bind.annotation.PathVariable;
-import org.springframework.web.bind.annotation.PostMapping;
-import org.springframework.web.bind.annotation.RequestBody;
-
-/**
- * The RESTful API Controller Class
- * The URL for this API Controller is '/api/v1'
- * 
- * NOTE: By adding @CrossOrigin, Swagger preview can work perfectly.
- * 
- */
-@RestController
-@CrossOrigin
-@RequestMapping(value = "/api/v1")
-public class UserController {
-    @Autowired
-    private UserService userService;
-
-    /**
-     * Get the user(s) by id (using query-string param)
-     * 
-     * @param id The ID for
-     * @return User object in JSON
-     */
-    @GetMapping(value = "users", produces = "application/json")
-    public List<User> getUsers() {
-        List<User> users = userService.getUsers();
-        return users;
-
-    }
-
-    @GetMapping(value = "users/{id}", produces = "application/json")
-    public User getUsersById(@PathVariable("id") String userId) {
-        User user = userService.getUserById(Integer.parseInt(userId));
-        return user;
-
-    }
-
-    @PostMapping("users")
-    public User insertUser(@RequestBody User user) {
-        // TODO: Return always 1, need to fix
-        int id = userService.insertUser(user);
-        user.setId(id);
-        return user;
-    }
-
-}

src/main/java/com/badbuta/learnspringbootrestfulsqlite/mapper/UserMapper.java

@@ -1,15 +0,0 @@
-package com.badbuta.learnspringbootrestfulsqlite.mapper;
-
-import java.util.List;
-import org.springframework.stereotype.Repository;
-
-import com.badbuta.learnspringbootrestfulsqlite.entities.User;
-
-@Repository
-public interface UserMapper {
-    int insertUser(User user);
-
-    User getUserById(int id);
-
-    List<User> getUsers();
-}

src/main/java/com/badbuta/learnspringbootrestfulsqlite/services/UserService.java

@@ -1,30 +0,0 @@
-package com.badbuta.learnspringbootrestfulsqlite.services;
-
-import java.util.List;
-
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.stereotype.Service;
-
-import com.badbuta.learnspringbootrestfulsqlite.entities.User;
-import com.badbuta.learnspringbootrestfulsqlite.mapper.UserMapper;
-
-@Service
-public class UserService {
-    @Autowired
-    UserMapper userMapper;
-
-    public int insertUser(User user) {
-        int insteredUserId = userMapper.insertUser(user);
-        return insteredUserId;
-    }
-
-    public User getUserById(int id) {
-        return userMapper.getUserById(id);
-    }
-
-    public List<User> getUsers() {
-        // Map<String, User> users = userMapper.getUsers();
-        // return users.values().toArray(new User[0]);
-        return userMapper.getUsers();
-    }
-}

src/main/java/com/example/demo/MainApplication.java

@@ -1,11 +1,11 @@
-package com.badbuta.learnspringbootrestfulsqlite;
+package com.example.demo;
 
 import org.mybatis.spring.annotation.MapperScan;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 
 @SpringBootApplication
-@MapperScan("com.badbuta.learnspringbootrestfulsqlite.mapper")
+@MapperScan("com.example.demo.repository")
 public class MainApplication {
 
 	public static void main(String[] args) {

src/main/java/com/example/demo/controller/DefaultController.java

@@ -0,0 +1,37 @@
+package com.example.demo.controller;
+
+import org.springframework.web.bind.annotation.RestController;
+
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.bind.annotation.ResponseBody;
+
+import org.springframework.web.bind.annotation.CrossOrigin;
+
+/**
+ * The default controller (i.e. No specific purpose)
+ * This controller handle root path and other testing/trying purpose path
+ * 
+ * NOTE: By adding @CrossOrigin, Swagger preview can work perfectly.
+ * 
+ */
+@RestController
+@CrossOrigin
+@RequestMapping(value = "/")
+public class DefaultController {
+
+    // @Value("${mybatis.config-location}")
+    // private String myBatisConfigLocation;
+
+    /**
+     * Root path /
+     * 
+     * @return Simple text
+     */
+    @RequestMapping(value = "/", method = RequestMethod.GET)
+    @ResponseBody
+    public String getRoot() {
+        // String myBatisConfigPath = myBatisConfigLocation.split(":")[1];
+        return "Hello, This is a self-learning project for spring boot for rest api using sqlite";
+    }
+}

src/main/java/com/example/demo/controller/UserController.java

@@ -0,0 +1,84 @@
+package com.example.demo.controller;
+
+import org.springframework.web.bind.annotation.RestController;
+
+import com.example.demo.model.User;
+import com.example.demo.services.UserService;
+
+import org.springframework.web.bind.annotation.RequestMapping;
+import java.util.List;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.CrossOrigin;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+
+/**
+ * The Controller Class for User API
+ * 
+ * NOTE: By adding @CrossOrigin, Swagger preview can work perfectly.
+ * 
+ * TODO:
+ * 1) How to set response content type to json by default
+ * 2) Handling errors
+ */
+@RestController
+@CrossOrigin
+@RequestMapping(value = "/api/v1/users")
+public class UserController {
+    @Autowired
+    private UserService userService;
+
+    /**
+     * Get all users
+     * 
+     * Method: GET
+     * Endpoint: /users or /users/
+     * 
+     * @return List of User object
+     */
+    @GetMapping(value = { "", "/" }, produces = "application/json")
+    public List<User> getUsers() {
+        List<User> users = userService.getUsers();
+        return users;
+
+    }
+
+    /**
+     * Get the user by id
+     * 
+     * Method: GET
+     * Endpoint: /users/{id}
+     * 
+     * TODO:
+     * 1) Return 404 if not found
+     * 2) Return correct status code like 200
+     * 
+     * @param userId the userId (= path variable {id})
+     * @return The User object. Empty content will be returned if not found
+     */
+    @GetMapping(value = "{id}", produces = "application/json")
+    public User getUsersById(@PathVariable("id") String userId) {
+        User user = userService.getUserById(Integer.parseInt(userId));
+        return user;
+
+    }
+
+    /**
+     * Add a user
+     * 
+     * Method: POST
+     * Endpoint: /users
+     * 
+     * @param user The User object with required fields. See swagger file
+     * @return The added user object
+     */
+    @PostMapping(value = "", produces = "application/json")
+    public User addUser(@RequestBody User user) {
+        int id = userService.addUser(user);
+        // if success, get the user and return the created user
+        User addedUser = userService.getUserById(id);
+        return addedUser;
+    }
+}

src/main/java/com/example/demo/model/User.java

@@ -1,4 +1,4 @@
-package com.badbuta.learnspringbootrestfulsqlite.entities;
+package com.example.demo.model;
 
 /**
  * Domain class - User
@@ -9,6 +9,8 @@ public class User {
     private String name;
     private String password;
 
+    public User() {
+    }
 
     public int getId() {
         return this.id;
@@ -37,10 +39,10 @@ public class User {
     @Override
     public String toString() {
         return "{" +
-            " id='" + getId() + "'" +
-            ", name='" + getName() + "'" +
-            ", password='" + getPassword() + "'" +
-            "}";
+                " id='" + getId() + "'" +
+                ", name='" + getName() + "'" +
+                ", password='" + getPassword() + "'" +
+                "}";
     }
-    
+
 }

src/main/java/com/example/demo/repository/UserMapper.java

@@ -0,0 +1,31 @@
+package com.example.demo.repository;
+
+import java.util.List;
+
+import org.springframework.stereotype.Repository;
+
+import com.example.demo.model.User;
+
+/**
+ * The Mapper class for User
+ * Note:
+ * 1) @MapperScan("<this package>") has to be added in main application source
+ * code.
+ * 2) Since MyBatis+SQLite is used, we should use MyBatis-specific approach for
+ * repositories. JpaRepository cannot be used.
+ * JpaRepository is part of Spring Data JPA, and it's designed to work with JPA
+ * (Java Persistence API) implementations, which include Hibernate, EclipseLink,
+ * and other JPA providers. It's not intended to be used with MyBatis.
+ * 
+ * @see com.example.demo.MainApplication
+ * 
+ */
+@Repository
+public interface UserMapper {
+
+    int addUser(User user);
+
+    User getUserById(int id);
+
+    List<User> getUsers();
+}

src/main/java/com/example/demo/repository/UserMapper.xml

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<!DOCTYPE mapper
+        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
+        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
+<mapper namespace="com.example.demo.repository.UserMapper">
+    <!-- Get all users -->
+    <select id="getUsers" resultType="User">
+        select * from users
+    </select>
+
+    <!-- Add user -->
+    <insert id="addUser" parameterType="User" useGeneratedKeys="true" keyProperty="id" keyColumn="id">
+        insert into users (name, password) values (#{name}, #{password})
+        <!-- NOTE: com.xerial sqlite-jdbc driver does not supporting RETURN_GENERATED_KEYS and useGeneratedKeys will cause error -->
+        <!-- Uncomment the follow <selectKey> to fix the problem -->
+        <!-- <selectKey keyProperty="id" order="AFTER" resultType="int">
+            SELECT last_insert_rowid() as id
+        </selectKey> -->
+    </insert>
+
+    <!-- Get user by id  -->
+    <select id="getUserById" parameterType="int" resultType="User">
+        select *
+        from users
+        where id = #{id};
+    </select>
+</mapper>

src/main/java/com/example/demo/services/UserService.java

@@ -0,0 +1,53 @@
+package com.example.demo.services;
+
+import java.util.List;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+import com.example.demo.model.User;
+import com.example.demo.repository.UserMapper;
+
+/**
+ * Service class for User
+ */
+@Service
+public class UserService {
+    @Autowired
+    UserMapper userMapper;
+
+    /**
+     * Add the user
+     * 
+     * @param user The user object for adding
+     * @return Added user's id
+     */
+    public int addUser(User user) {
+        // NOTE: the mapper will return the number of row inserted
+        // not the generated ID.
+        // int rowInserted = userMapper.addUser(user);
+
+        userMapper.addUser(user);
+        return user.getId();
+    }
+
+    /**
+     * Get user by id
+     * 
+     * @param id user id
+     * @return The user, null will be returned if not exist.
+     */
+    public User getUserById(int id) {
+        return userMapper.getUserById(id);
+    }
+
+    /**
+     * Get all user (without pagination)
+     * NOTE: It will cause problem if the number of record is large.
+     * 
+     * @return A list of User object. The result.
+     */
+    public List<User> getUsers() {
+        return userMapper.getUsers();
+    }
+}

src/main/resources/application.properties

@@ -1,13 +1,23 @@
-# Setting used by @Repository
+## ----- Database configuration -----
+
+# Datasource URL used by @Repository, the db file location is /data/mainapp.sqlite3
 spring.datasource.url=jdbc:sqlite:data/mainapp.sqlite3
+
+# Datasource URL used by @Repository, the db use in-memory
+# spring.datasource.url=jdbc:sqlite::memory:
+
 spring.datasource.driver-class-name=org.sqlite.JDBC
 # spring.datasource.username=
 # spring.datasource.password=
 
-# MyBatis related:
+## MyBatis related:
 # mybatis.check-config-location=true
-# mybatis.mapper-locations=classpath:mapper/*.xml
-# mybatis.type-aliases-package=com.badbuta.learnspringbootrestfulsqlite.entities
 mybatis.config-location=classpath:mybatis/mybatis-config.xml
 
+## ----- Logger configuration -----
+logging.level.org.mybatis=DEBUG
+# logging.level.root=DEBUG
+
+
+## ----- Others configuration -----
 server.port=8888

src/main/resources/mapping/UserMapper.xml

@@ -1,29 +0,0 @@
-<?xml version="1.0" encoding="UTF-8" ?>
-<!DOCTYPE mapper
-        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
-        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
-<mapper namespace="com.badbuta.learnspringbootrestfulsqlite.mapper.UserMapper">
-    <select id="getUsers" resultType="User">
-        select * from users
-    </select>
-
-    <!-- NOTE: Sqlite JDBC driver not supporting RETURN_GENERATED_KEYS -->
-    <insert id="insertUser" parameterType="User" keyProperty="id">
-        <selectKey order="AFTER" keyProperty="id" resultType="int">
-            SELECT last_insert_rowid()
-        </selectKey>
-        insert into users (name,password) values (#{name},#{password})
-    </insert>
-
-    <select id="getUserById" parameterType="int" resultType="User">
-        select *
-        from users
-        where id = #{id};
-    </select>
-
-    <!-- <resultMap id="UserM" type="com.badbuta.learnspringbootrestfulsqlite.entities.User">
-        <result property="id" column="id" />
-        <result property="name" column="name" />
-        <result property="password" column="password" />
-    </resultMap> -->
-</mapper>

src/main/resources/mybatis/mybatis-config.xml

@@ -5,10 +5,12 @@
 <configuration>
     <!-- In order to use the application setting here, we need to set the <properties> -->
     <properties resource="application.properties"/>
+
     <typeAliases>
         <!-- Equivent to application.properties: mybatis.type-aliases-package -->
-        <package name="com.badbuta.learnspringbootrestfulsqlite.entities"></package>
+        <package name="com.example.demo.model"></package>
     </typeAliases>
+    
     <environments default="development">
         <environment id="development">
             <transactionManager type="JDBC"/>
@@ -18,7 +20,10 @@
             </dataSource>
         </environment>
     </environments>
-    <mappers>
-        <mapper resource="mapping/UserMapper.xml"/>
-    </mappers>
+    
+    <!-- If the *Mapper.xml is placed in the java source folder, we don't need to specify it explicitly -->
+    <!-- <mappers>
+        <mapper resource="mapper/UserMapper.xml"/>
+    </mappers> -->
+    
 </configuration>

src/test/java/com/example/demo/MainApplicationTests.java

@@ -1,4 +1,4 @@
-package com.badbuta.learnspringbootrestfulsqlite;
+package com.example.demo;
 
 import org.junit.jupiter.api.Test;
 import org.springframework.boot.test.context.SpringBootTest;