Java Web系列：Spring Boot 基础

Spring Boot 项目（参考1） 提供了一个类似ASP.NET MVC的默认模板一样的标准样板，直接集成了一系列的组件并使用了默认的配置。使用Spring Boot 不会降低学习成本，甚至增加了学习成本，但显著降低了使用成本并提高了开发效率。如果没有Spring基础不建议直接上手。

1.基础项目

这里只关注基于Maven的项目构建，使用Spring Boot CLI命令行工具和Gradle构建方式请参考官网。

（1）创建项目：

创建类型为quickstart的Maven项目，删除默认生成的.java文件保持默认的Maven目录即可。

（2）修改/pom.xml

 <?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.example</groupId>
     <artifactId>myproject</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <properties>
         <java.version>1.8</java.version>
     </properties>
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
         <version>1.3.1.RELEASE</version>
     </parent>
     <dependencies>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-web</artifactId>
         </dependency>
     </dependencies>
 </project>

（3）添加/src/main/sample/controller/HomeController.java文件：

 package simple.controller;

 import org.springframework.web.bind.annotation.*;

 @RestController
 public class HomeController {

     @RequestMapping("/")
     public String index() {
         return "Hello World!";
     }
 }

（4）添加/src/main/sample/Application.java文件：

 package simple;

 import org.springframework.boot.*;
 import org.springframework.boot.autoconfigure.*;
 import simple.controller.*;

 @EnableAutoConfiguration
 public class Application {

     public static void main(String[] args) throws Exception {
         SpringApplication.run(new Object[] { Application.class, HomeController.class }, args);
     }

 }

在浏览器中输入http://localhost:8080/，即可直接看到"Hello World"运行结果。

2. 添加数据访问支持

（1）修改pom，添加spring-boot-starter-data-jpa和h2依赖:

 <?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.example</groupId>
     <artifactId>myproject</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <properties>
         <java.version>1.8</java.version>
     </properties>
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
         <version>1.3.1.RELEASE</version>
     </parent>
     <dependencies>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-web</artifactId>
         </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-data-jpa</artifactId>
         </dependency>
         <dependency>
             <groupId>com.h2database</groupId>
             <artifactId>h2</artifactId>
             <scope>runtime</scope>
         </dependency>
     </dependencies>
 </project>

如果需要在控制台查看生成SQL语句，可以添加/src/main/resources/application.properties

 spring.h2.console.enabled=true
 logging.level.org.hibernate.SQL=debug

（2）添加实体

添加User、Role、Category和Post实体。

User:

 package simple.domain;

 import java.util.*;

 import javax.persistence.*;

 @Entity
 public class User {
     @Id
     @GeneratedValue
     private Long id;

     private String userName;

     private String password;

     private String Email;

     @javax.persistence.Version
     private Long Version;

     @ManyToMany(cascade = CascadeType.ALL)
     private List<Role> roles = new ArrayList<Role>();

     public Long getId() {
         return id;
     }

     public void setId(Long id) {
         this.id = id;
     }

     public String getUserName() {
         return userName;
     }

     public void setUserName(String userName) {
         this.userName = userName;
     }

     public String getPassword() {
         return password;
     }

     public void setPassword(String password) {
         this.password = password;
     }

     public String getEmail() {
         return Email;
     }

     public void setEmail(String email) {
         Email = email;
     }

     public List<Role> getRoles() {
         return roles;
     }

     public void setRoles(List<Role> roles) {
         this.roles = roles;
     }

     public Long getVersion() {
         return Version;
     }

     public void setVersion(Long version) {
         Version = version;
     }
 }

Role:

 package simple.domain;

 import java.util.*;

 import javax.persistence.*;

 @Entity
 public class Role {
     @Id
     @GeneratedValue
     private Long id;

     private String roleName;

     @ManyToMany(cascade = CascadeType.ALL)
     private List<User> users = new ArrayList<User>();

     public Long getId() {
         return id;
     }

     public void setId(Long id) {
         this.id = id;
     }

     public String getRoleName() {
         return roleName;
     }

     public void setRoleName(String roleName) {
         this.roleName = roleName;
     }

     public List<User> getUsers() {
         return users;
     }

     public void setUsers(List<User> users) {
         this.users = users;
     }
 }

Category:

 package simple.domain;

 import java.util.*;

 import javax.persistence.*;

 @Entity
 public class Category {
     @Id
     @GeneratedValue
     private Long id;

     private String Name;

     @OneToMany
     private List<Post> posts = new ArrayList<Post>();

     public Long getId() {
         return id;
     }

     public void setId(Long id) {
         this.id = id;
     }

     public String getName() {
         return Name;
     }

     public void setName(String name) {
         Name = name;
     }

     public List<Post> getPosts() {
         return posts;
     }

     public void setPosts(List<Post> posts) {
         this.posts = posts;
     }
 }

Post:

 package simple.domain;

 import java.util.*;

 import javax.persistence.*;

 @Entity
 public class Post {
     @Id
     @GeneratedValue
     private Long id;

     private String Name;

     private String Html;

     private String Text;

     private Date CreateAt;

     @ManyToOne
     private Category category;

     public Long getId() {
         return id;
     }

     public void setId(Long id) {
         this.id = id;
     }

     public String getName() {
         return Name;
     }

     public void setName(String name) {
         Name = name;
     }

     public String getHtml() {
         return Html;
     }

     public void setHtml(String html) {
         Html = html;
     }

     public String getText() {
         return Text;
     }

     public void setText(String text) {
         Text = text;
     }

     public Date getCreateAt() {
         return CreateAt;
     }

     public void setCreateAt(Date createAt) {
         CreateAt = createAt;
     }

     public Category getCategory() {
         return category;
     }

     public void setCategory(Category category) {
         this.category = category;
     }
 }

（3）添加资源库

添加UserRepository、RoleRepository、CategoryRepository和PostRepository接口，无需实现。

UserRepository:

 package simple.repository;

 import org.springframework.data.repository.*;

 import simple.domain.*;

 public interface UserRepository extends CrudRepository<User, Long> {

 }

RoleRepository

 package simple.repository;

 import org.springframework.data.repository.*;

 import simple.domain.*;

 public interface RoleRepository extends CrudRepository<Role, Long> {

 }

CategoryRepository

 package simple.repository;

 import org.springframework.data.repository.*;

 import simple.domain.*;

 public interface CategoryRepository extends CrudRepository<Category, Long> {

 }

PostRepository

package simple.repository;

import org.springframework.data.repository.*;

import simple.domain.*;

public interface PostRepository extends CrudRepository<User, Long> {

}

（4）在控制器中注入资源库接口

 package simple.controller;

 import org.springframework.beans.factory.annotation.*;
 import org.springframework.web.bind.annotation.*;

 import simple.repository.*;

 @RestController
 public class HomeController {

     private UserRepository userRepository;
     private RoleRepository roleRepository;
     private CategoryRepository categoryRepository;
     private PostRepository postReppository;

     @Autowired
     public HomeController(UserRepository userRepository, RoleRepository roleRepository,
             CategoryRepository categoryRepository, PostRepository postReppository) {
         this.userRepository = userRepository;
         this.roleRepository = roleRepository;
         this.categoryRepository = categoryRepository;
         this.postReppository = postReppository;
     }

     @RequestMapping("/")
     public long index() {
         return userRepository.count();
     }
 }

使用事务时在方法上应用注解@Transactional

3.添加验证和授权支持

（1）添加spring-boot-starter-security依赖

 <?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.example</groupId>
     <artifactId>myproject</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <properties>
         <java.version>1.8</java.version>
     </properties>
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
         <version>1.3.1.RELEASE</version>
     </parent>
     <dependencies>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-web</artifactId>
         </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-data-jpa</artifactId>
         </dependency>
         <dependency>
             <groupId>com.h2database</groupId>
             <artifactId>h2</artifactId>
             <scope>runtime</scope>
         </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-security</artifactId>
         </dependency>
     </dependencies>
 </project>

（2）修改Application.java

 package simple;

 import org.springframework.boot.*;
 import org.springframework.boot.autoconfigure.*;
 import org.springframework.context.annotation.Bean;
 import org.springframework.security.config.annotation.method.configuration.*;
 import org.springframework.security.config.annotation.web.builders.HttpSecurity;
 import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
 import org.springframework.security.web.authentication.SavedRequestAwareAuthenticationSuccessHandler;

 import simple.controller.*;

 @EnableAutoConfiguration
 @EnableGlobalMethodSecurity(securedEnabled = true, prePostEnabled = true)
 public class Application {

     public static void main(String[] args) throws Exception {
         SpringApplication.run(new Object[] { Application.class, HomeController.class }, args);
     }

     @Bean
     public WebSecurityConfigurerAdapter webSecurityConfigurerAdapter() {
         return new MyWebSecurityConfigurer();
     }

     public static class MyWebSecurityConfigurer extends WebSecurityConfigurerAdapter {
         @Override
         protected void configure(HttpSecurity http) throws Exception {
             http.csrf().disable();
             http.authorizeRequests().antMatchers("/account**", "/admin**").authenticated();
             http.formLogin().usernameParameter("userName").passwordParameter("password").loginPage("/login")
                     .loginProcessingUrl("/login").successHandler(new SavedRequestAwareAuthenticationSuccessHandler())
                     .and().logout().logoutUrl("/logout").logoutSuccessUrl("/");
             http.rememberMe().rememberMeParameter("rememberMe");

         }
     }
 }

访问http://localhost:8080/account会自动跳转到login登录页。Spring Security的具体使用前文已有所述。

参考：

（1）https://github.com/spring-projects/spring-boot

（2）http://projects.spring.io/spring-boot/

（3）https://github.com/qibaoguang/Spring-Boot-Reference-Guide/blob/master/SUMMARY.md