SpringBoot实战(三)之使用RestFul Web服务
一、导入maven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>org.springframework</groupId> <artifactId>gs-consuming-rest</artifactId> <version>0.1.0</version> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.8.RELEASE</version> </parent> <properties> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter</artifactId> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-web</artifactId> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project> 二、构建实体 Quote.java package hello; import com.fasterxml.jackson.annotation.JsonIgnoreProperties; @JsonIgnoreProperties(ignoreUnknown = true) public class Quote { private String type; private Value value; public Quote() { } public String getType() { return type; } public void setType(String type) { this.type = type; } public Value getValue() { return value; } public void setValue(Value value) { this.value = value; } @Override public String toString() { return "Quote{" + "type='" + type + '\'' + ", value=" + value + '}'; } } Value.java package hello; import com.fasterxml.jackson.annotation.JsonIgnoreProperties; @JsonIgnoreProperties(ignoreUnknown = true) public class Value { private Long id; private String quote; public Value() { } public Long getId() { return this.id; } public String getQuote() { return this.quote; } public void setId(Long id) { this.id = id; } public void setQuote(String quote) { this.quote = quote; } @Override public String toString() { return "Value{" + "id=" + id + ", quote='" + quote + '\'' + '}'; } } @JsonIgnore注解用来忽略某些字段，可以用在Field或者Getter方法上，用在Setter方法时，和Filed效果一样。这个注解只能用在POJO存在的字段要忽略的情况，不能满足现在需要的情况。 @JsonIgnoreProperties(ignoreUnknown = true)，将这个注解写在类上之后，就会忽略类中不存在的字段，可以满足当前的需要。这个注解还可以指定要忽略的字段。使用方法如下： @JsonIgnoreProperties({ "internalId", "secretKey" })指定的字段不会被序列化和反序列化。 三、编写启动类 package hello; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.web.client.RestTemplate; public class Application { private static final Logger log = LoggerFactory.getLogger(Application.class); public static void main(String args[]) { RestTemplate restTemplate = new RestTemplate(); Quote quote = restTemplate.getForObject("http://gturnquist-quoters.cfapps.io/api/random", Quote.class); log.info(quote.toString()); } } 运行后控制台显示结果为: package hello; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.boot.CommandLineRunner; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.boot.web.client.RestTemplateBuilder; import org.springframework.context.annotation.Bean; import org.springframework.web.client.RestTemplate; @SpringBootApplication public class Application { private static final Logger log = LoggerFactory.getLogger(Application.class); public static void main(String args[]) { SpringApplication.run(Application.class); } @Bean public RestTemplate restTemplate(RestTemplateBuilder builder) { return builder.build(); } @Bean public CommandLineRunner run(RestTemplate restTemplate) throws Exception { return args -> { Quote quote = restTemplate.getForObject( "http://gturnquist-quoters.cfapps.io/api/random", Quote.class); log.info(quote.toString()); }; } } 它RestTemplateBuilder是由Spring注入的，如果你使用它来创建一个，RestTemplate那么你将受益于Spring Boot中带有消息转换器和请求工厂的所有自动配置。我们还将其提取RestTemplate为a@Bean以使其更容易测试（可以通过这种方式更容易地进行模拟）。 最后执行mvn clean install或者mvn install，生成jar包，通过cmd命令执行java -jar gs-consume-rest-0.1.0.jar 出现如红色标记处，表示成功开发一个RestFul客户端。
