APP的接口版本管理 实现多版本共存
思路：用户请求url ---> 拦截器拦截 ---> 转发到真正处理类和方法 ---> 返回结果
url注解类
package com.jc.app.util.apiVersion;
import java.lang.annotation.*;
/**
* 需要拦截的API接口方法
* Created by jasonzhu on 2016/11/28.
*/
@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface ApiVersion {
/**
* 指定执行操作的类名
*/
Class targetClass();
/**
* 指定执行操作的方法名前缀
*/
String methodPreName() default "";
}
执行处理方法参数注解类
package com.jc.app.util.apiVersion;
import java.lang.annotation.*;
/**
* 处理方法的参数注解
* Created by jasonzhu on 2016/11/30.
*/
@Target({ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface ApiParam {
/**
* 参数名
*/
String value();
/**
* 是否必须有值 默认必须有
*/
boolean required() default true;
/**
* 值非必须时 如果未传值 默认值
*/
DefaultValueEnum defaultValue() default DefaultValueEnum.DEFAULT;
}
默认值枚举
package com.jc.app.util.apiVersion;
/**
* 默认参数值
* Created by jasonzhu on 2016/11/30.
*/
public enum DefaultValueEnum {
/**
* 按照类型赋默认值
* String ""
* Boolean false
* Integer 0
* Long 0
* 其他 null
*/
DEFAULT,
NULL,
STRING_EMPTY,
ZERO,
FALSE,
TRUE
}
异常
package com.jc.app.util.apiVersion;
/**
* 版本控制异常
* Created by jasonzhu on 2016/11/30.
*/
public class ApiVersionException extends RuntimeException {
public ApiVersionException(String message) {
super(message);
}
public ApiVersionException(String message, Throwable cause) {
super(message, cause);
}
}
版本拦截器
package com.jc.app.util.apiVersion;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.PrintWriter;
import java.lang.annotation.Annotation;
import java.lang.reflect.Method;
import java.math.BigDecimal;
import java.util.Map;
/**
* 接口版本拦截器
* Created by jasonzhu on 2016/11/28.
*/
public class ApiVersionInterceptor extends HandlerInterceptorAdapter {
/**
* 接口版本参数名
*/
final String API_VERSION = "av";
final String STRING_DEFAULT = "";
final Integer INTEGER_DEFAULT = 0;
final Long LONG_DEFAULT = 0L;
final Boolean BOOLEAN_DEFAULT = false;
@Autowired
private ApplicationContext context;
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
if (!(handler instanceof HandlerMethod)) {
return true;
}
HandlerMethod method = (HandlerMethod) handler;
ApiVersion apiVersion = method.getMethodAnnotation(ApiVersion.class);
//判断是否纳入接口版本控制
if (apiVersion == null) {
return true;
}
Class cls = apiVersion.targetClass();
Object o;
try {
o = context.getBean(cls);
} catch (Exception e) {
throw new ApiVersionException("指定的处理类必须纳入spring的bean管理", e);
}
String preName = apiVersion.methodPreName();
if (preName == null || preName.trim().isEmpty()) {
preName = method.getMethod().getName();
}
//接口版本号
String av = "1";
//参数列表
Map requestParam = request.getParameterMap();
if (requestParam.get(API_VERSION) != null) {
av = requestParam.get(API_VERSION)[0];
}
Method[] methods = cls.getMethods();
if (methods == null) {
writeMsg(response, "未找到响应方法");
return false;
}
Method targetMethod = null;
//找到指定的处理方法
for (Method me : methods) {
if (me.getName().equals(preName + av)) {
targetMethod = me;
break;
}
}
if (targetMethod == null) {
writeMsg(response, "非法请求");
return false;
}
if (!targetMethod.getReturnType().equals(String.class)) {
throw new ApiVersionException("响应方法返回类型必须为String :" + targetMethod.getName());
}
//获得方法的参数
Class[] paramTypes = targetMethod.getParameterTypes();
Integer paramLength = paramTypes.length;
//调动方法的参数
Object[] paramList = new Object[paramLength];
Annotation[][] annotationss = targetMethod.getParameterAnnotations();
//总注解参数个数
for (int i = 0; i < annotationss.length; i++) {
Annotation[] annotations = annotationss[i];
if (annotations.length < 1)
throw new ApiVersionException("存在未添加@ApiParam注解参数的方法 :" + targetMethod.getName());
//是否存在ApiParam注解
boolean hasAnn = false;
for (int j = 0; j < annotations.length; j++) {
Annotation annotation = annotations[j];
if (annotation instanceof ApiParam) {
//为参数赋值
paramList[i] = getParam(requestParam, (ApiParam) annotation, paramTypes[i]);
hasAnn = true;
break;
}
}
if (!hasAnn)
throw new ApiVersionException("存在未添加@ApiParam注解参数的方法 :" + targetMethod.getName());
}
//反射方法调用
String result = (String) targetMethod.invoke(o, paramList);
writeMsg(response, result);
return false;
}
/**
* 输出内容
*
* @param response
* @param msg
* @throws Exception
*/
private void writeMsg(HttpServletResponse response, String msg) throws Exception {
response.setContentType("application/json;charset=UTF-8");
PrintWriter out = response.getWriter();
out.println(msg);
out.flush();
out.close();
}
/**
* 获得参数的值
*
* @param requestParam 请求参数
* @param apiParam 参数上注解
* @param paramType 参数类型
* @return 参数值
*/
private Object getParam(Map requestParam, ApiParam apiParam, Class paramType) {
String reqName = apiParam.value();
//如果有该参数
if (requestParam.get(reqName) != null) {
Object o = requestParam.get(reqName)[0];
try {
if (paramType.equals(String.class)) {
return String.valueOf(o);
}
if (paramType.equals(Boolean.class) || "boolean".equals(paramType.getName())) {
return Boolean.parseBoolean(o.toString());
}
if (paramType.equals(Integer.class) || "int".equals(paramType.getName())) {
return Integer.parseInt(o.toString());
}
if (paramType.equals(Long.class) || "long".equals(paramType.getName())) {
return Long.parseLong(o.toString());
}
if (paramType.equals(BigDecimal.class)) {
return new BigDecimal(o.toString());
}
} catch (Exception e) {
throw new ApiVersionException("参数格式化失败 :" + reqName, e);
}
return o;
}
//如果参数必须
if (apiParam.required()) {
throw new ApiVersionException("缺少参数 :" + reqName);
}
//返回默认值
DefaultValueEnum dfe = apiParam.defaultValue();
if (DefaultValueEnum.DEFAULT.equals(dfe)) {
if (paramType.equals(String.class)) {
return STRING_DEFAULT;
}
if (paramType.equals(Boolean.class) || "boolean".equals(paramType.getName())) {
return BOOLEAN_DEFAULT;
}
if (paramType.equals(Integer.class) || "int".equals(paramType.getName())) {
return INTEGER_DEFAULT;
}
if (paramType.equals(Long.class) || "long".equals(paramType.getName())) {
return LONG_DEFAULT;
}
} else if (DefaultValueEnum.NULL.equals(dfe)) {
return null;
} else if (DefaultValueEnum.STRING_EMPTY.equals(dfe)) {
return "";
} else if (DefaultValueEnum.ZERO.equals(dfe)) {
return 0;
} else if (DefaultValueEnum.FALSE.equals(dfe)) {
return false;
} else if (DefaultValueEnum.TRUE.equals(dfe)) {
return true;
}
return null;
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
}
}
spring mvc中增加的配置
controller
package com.jc.app.controller;
import com.jc.app.util.apiVersion.ApiVersion;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
/**
* 测试版本控制接口
* Created by jasonzhu on 2016/12/1.
*/
@RestController
public class TestApiVersionController {
@ApiVersion(targetClass = TestApiVersionDo.class)
@RequestMapping("/api/test")
public void test(){}
@ApiVersion(targetClass = TestApiVersionDo.class,methodPreName = "test")
@RequestMapping("/api/testno")
public void testNo(){}
}
真正执行方法的类
package com.jc.app.controller;
import com.jc.app.util.apiVersion.ApiParam;
import com.jc.app.util.apiVersion.DefaultValueEnum;
import org.springframework.stereotype.Component;
import java.math.BigDecimal;
/**
* 版本拦截器之后真正执行的方法
* Created by jasonzhu on 2016/12/1.
*/
@Component
public class TestApiVersionDo {
public void test1(){}
private String test2(){return "调用成功 没有参数";}
public String test3(){
return "调用成功 没有参数";
}
public String test4(@ApiParam("a") String app){
return "调用成功 一个参数 app:"+app;
}
public String test5(@ApiParam("av") Integer av,@ApiParam("a") String app,@ApiParam(value = "b",required = false) String b){
return "调用成功 三个参数 app:"+app+" av:"+av+" b:"+b;
}
public String test6(@ApiParam("amount") BigDecimal amount, @ApiParam(value = "l",required = false) long l, @ApiParam(value = "b",required = false,defaultValue = DefaultValueEnum.TRUE) Boolean b){
return "调用成功 三个参数 amount:"+amount+" l:"+l+" b:"+b;
}
}