简介
相信很多人都接触spring框架很长时间了，每次搭建spring框架的时候都需要配置好多的jar、xml，做很多繁琐重复的配置，稍微不留神就会出现各种各样的问题，每次调试真的是香菇、蓝瘦啊。
spring boot的出现帮助我们彻底解决了这些jar的依赖，只需要很少的配置就可以完成我们的开发工作，我们可以把自己的应用打包成jar，使用java -jar来运行spring web应用，spring boot集成了很多的web容器，后面都会慢慢讲到这些，今天我们就开始使用spring boot完成一个最简单的web应用。
使用maven构建项目
spring官网提供了了一个非常方便的地址来帮助我们创建spring boot项目，http://start.spring.io/ ，输入相关参数点击 Generate Project 即可下载自动生成的压缩包。
该项目采用maven构建，加压后直接使用自己的IDE导入maven工程即可
1，打开pom文件就可以看到新的项目比传统的spring mvc项目的pom文件接口清晰了很多
1 <parent> 2 <groupId>org.springframework.boot</groupId> 3 <artifactId>spring-boot-starter-parent</artifactId> 4 <version>1.4.1.RELEASE</version> 5 </parent>
第一个地方是多了上面的代码，这个spring boot会自动帮我门引入一些约定的配置，查看源码得知
1 <?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">
2 <modelVersion>4.0.0</modelVersion>
3 <parent>
4 <groupId>org.springframework.boot</groupId>
5 <artifactId>spring-boot-dependencies</artifactId>
6 <version>1.4.1.RELEASE</version>
7 <relativePath>../../spring-boot-dependencies</relativePath>
8 </parent>
9 <artifactId>spring-boot-starter-parent</artifactId>
10 <packaging>pom</packaging>
11 <name>Spring Boot Starter Parent</name>
12 <description>Parent pom providing dependency and plugin management for applications
13 built with Maven</description>
14 <url>http://projects.spring.io/spring-boot/</url>
15 <organization>
16 <name>Pivotal Software, Inc.</name>
17 <url>http://www.spring.io</url>
18 </organization>
19 <properties>
20 <java.version>1.6</java.version>
21 <resource.delimiter>@</resource.delimiter> <!-- delimiter that doesn‘t clash with Spring ${} placeholders -->
22 <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
23 <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
24 <maven.compiler.source>${java.version}</maven.compiler.source>
25 <maven.compiler.target>${java.version}</maven.compiler.target>
26 </properties>
27 <dependencyManagement>
28 <dependencies>
29 <dependency>
30 <groupId>org.springframework</groupId>
31 <artifactId>spring-core</artifactId>
32 <version>${spring.version}</version>
33 <exclusions>
34 <exclusion>
35 <groupId>commons-logging</groupId>
36 <artifactId>commons-logging</artifactId>
37 </exclusion>
38 </exclusions>
39 </dependency>
40 </dependencies>
41 </dependencyManagement>
42 <build>
43 <!-- Turn on filtering by default for application properties -->
44 <resources>
45 <resource>
46 <directory>${basedir}/src/main/resources</directory>
47 <filtering>true</filtering>
48 <includes>
49 <include>**/application*.yml</include>
50 <include>**/application*.properties</include>
51 </includes>
52 </resource>
53 <resource>
54 <directory>${basedir}/src/main/resources</directory>
55 <excludes>
56 <exclude>**/application*.yml</exclude>
57 <exclude>**/application*.properties</exclude>
58 </excludes>
59 </resource>
60 </resources>
61 <pluginManagement>
62 <plugins>
63 <!-- Apply more sensible defaults for user projects -->
64 <plugin>
65 <groupId>org.apache.maven.plugins</groupId>
66 <artifactId>maven-failsafe-plugin</artifactId>
67 <executions>
68 <execution>
69 <goals>
70 <goal>integration-test</goal>
71 <goal>verify</goal>
72 </goals>
73 </execution>
74 </executions>
75 </plugin>
76 <plugin>
77 <groupId>org.apache.maven.plugins</groupId>
78 <artifactId>maven-jar-plugin</artifactId>
79 <configuration>
80 <archive>
81 <manifest>
82 <mainClass>${start-class}</mainClass>
83 <addDefaultImplementationEntries>true</addDefaultImplementationEntries>
84 </manifest>
85 </archive>
86 </configuration>
87 </plugin>
88 <plugin>
89 <groupId>org.apache.maven.plugins</groupId>
90 <artifactId>maven-surefire-plugin</artifactId>
91 <configuration>
92 <includes>
93 <include>**/*Tests.java</include>
94 <include>**/*Test.java</include>
95 </includes>
96 <excludes>
97 <exclude>**/Abstract*.java</exclude>
98 </excludes>
99 </configuration>
100 </plugin>
101 <plugin>
102 <groupId>org.apache.maven.plugins</groupId>
103 <artifactId>maven-war-plugin</artifactId>
104 <configuration>
105 <failOnMissingWebXml>false</failOnMissingWebXml>
106 <archive>
107 <manifest>
108 <mainClass>${start-class}</mainClass>
109 <addDefaultImplementationEntries>true</addDefaultImplementationEntries>
110 </manifest>
111 </archive>
112 </configuration>
113 </plugin>
114 <plugin>
115 <groupId>org.codehaus.mojo</groupId>
116 <artifactId>exec-maven-plugin</artifactId>
117 <configuration>
118 <mainClass>${start-class}</mainClass>
119 </configuration>
120 </plugin>
121 <plugin>
122 <groupId>org.apache.maven.plugins</groupId>
123 <artifactId>maven-resources-plugin</artifactId>
124 <version>2.6</version>
125 <configuration>
126 <delimiters>
127 <delimiter>${resource.delimiter}</delimiter>
128 </delimiters>
129 <useDefaultDelimiters>false</useDefaultDelimiters>
130 </configuration>
131 </plugin>
132 <plugin>
133 <groupId>pl.project13.maven</groupId>
134 <artifactId>git-commit-id-plugin</artifactId>
135 <version>2.1.11</version>
136 <executions>
137 <execution>
138 <goals>
139 <goal>revision</goal>
140 </goals>
141 </execution>
142 </executions>
143 <configuration>
144 <verbose>true</verbose>
145 <dateFormat>yyyy-MM-dd‘T‘HH:mm:ssZ</dateFormat>
146 <generateGitPropertiesFile>true</generateGitPropertiesFile>
147 <generateGitPropertiesFilename>${project.build.outputDirectory}/git.properties</generateGitPropertiesFilename>
148 </configuration>
149 </plugin>
150 <!-- Support our own plugin -->
151 <plugin>
152 <groupId>org.springframework.boot</groupId>
153 <artifactId>spring-boot-maven-plugin</artifactId>
154 <executions>
155 <execution>
156 <goals>
157 <goal>repackage</goal>
158 </goals>
159 </execution>
160 </executions>
161 <configuration>
162 <mainClass>${start-class}</mainClass>
163 </configuration>
164 </plugin>
165 <!-- Support shade packaging (if the user does not want to use our plugin) -->
166 <plugin>
167 <groupId>org.apache.maven.plugins</groupId>
168 <artifactId>maven-shade-plugin</artifactId>
169 <dependencies>
170 <dependency>
171 <groupId>org.springframework.boot</groupId>
172 <artifactId>spring-boot-maven-plugin</artifactId>
173 <version>1.4.1.RELEASE</version>
174 </dependency>
175 </dependencies>
176 <configuration>
177 <keepDependenciesWithProvidedScope>true</keepDependenciesWithProvidedScope>
178 <createDependencyReducedPom>true</createDependencyReducedPom>
179 <filters>
180 <filter>
181 <artifact>*:*</artifact>
182 <excludes>
183 <exclude>META-INF/*.SF</exclude>
184 <exclude>META-INF/*.DSA</exclude>
185 <exclude>META-INF/*.RSA</exclude>
186 </excludes>
187 </filter>
188 </filters>
189 </configuration>
190 <executions>
191 <execution>
192 <phase>package</phase>
193 <goals>
194 <goal>shade</goal>
195 </goals>
196 <configuration>
197 <transformers>
198 <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
199 <resource>META-INF/spring.handlers</resource>
200 </transformer>
201 <transformer implementation="org.springframework.boot.maven.PropertiesMergingResourceTransformer">
202 <resource>META-INF/spring.factories</resource>
203 </transformer>
204 <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
205 <resource>META-INF/spring.schemas</resource>
206 </transformer>
207 <transformer implementation="org.apache.maven.plugins.shade.resource.ServicesResourceTransformer"/>
208 <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
209 <mainClass>${start-class}</mainClass>
210 </transformer>
211 </transformers>
212 </configuration>
213 </execution>
214 </executions>
215 </plugin>
216 </plugins>
217 </pluginManagement>
218 </build>
219 </project>
spring boot默认帮我引入的jdk版本是1.6，如果需要改动，则在自己pom文件中直接重写<java.version>1.6</java.version>即可。
还可以看到它已经帮我们引入了spring-core和commons-logging包
继续往下看可以发现一些属性文件他也帮我定义好了规则，不需要我们自己在xml中定义了，已经一些maven插件的定义这里就不一一说明 ，具体插件是做什么用的，各位可以看下maven的相关知识。
第二个改变的地方是
1 <dependency> 2 <groupId>org.springframework.boot</groupId> 3 <artifactId>spring-boot-starter</artifactId> 4 </dependency> 5 6 <dependency> 7 <groupId>org.springframework.boot</groupId> 8 <artifactId>spring-boot-starter-test</artifactId> 9 <scope>test</scope> 10 </dependency> 11 12 <dependency> 13 <groupId>org.springframework.boot</groupId> 14 <artifactId>spring-boot-starter-web</artifactId> 15 </dependency>
spring-boot-starter:核心模块，包括自动配置支持、日志
spring-boot-starter-test ：测试模块，包括JUnit、Hamcrest、Mockito
spring-boot-starter-web ：开发web项目依赖 代码编写说了这么多的配置，来让我们创建第一个class吧
@Controller
@EnableAutoConfiguration
@RequestMapping("/ctr")
public class SampleController
{
@RequestMapping("/getStr")
@ResponseBody
String home(){
return "Hello World";
}
@RequestMapping("/info")
@ResponseBody
public Map<String,String> getInfo(){
Map<String, String> map = new HashMap<>();
map.put("name", "jack");
return map;
}
public static void main(String[] args)
{
SpringApplication.run(SampleController.class,args);
}
}
到此为止，我们的第一个spring 的web项目就结束了，直接运行main方法，浏览器中输入：http://127.0.0.1:8080/ctr/info 可以看到运行结果 {"name": "jack"}
怎么样，是不是很神奇，没有启动任何的web容器，只需要执行main方法就可以运行我们的web项目了，而且配置就这么简单任性。
时间： 2024-11-20 13:35:00