如何实现@RequestMapping自定义属性

Question

作为一个例子，取子域映射。

然后，映射将如下所示：

@RequestMapping(value = "/path", headers="subdomain=www")
 public String subsiteIndexPage(Model model,HttpServletRequest request) { ... }

如果我们想创建自定义的@RequestMapping属性，例如子域。创建这样的映射：

@RequestMapping(value = "/some/action", subdomain = "www")
public String handlerFunction(){ ... }

我们应该使用我们自己的实现覆盖@RequestMapping @interface定义并覆盖RequestMappingHandlerMapping受保护的方法
（如JIRA所述：“ 允许自定义请求映射条件SPR-7812 ”）。

这样对吗？有人可以提供提示，如何实现此功能吗？

想法1：
正如原始的jira线程所建议的，是创建自己的实现RequestCondition

在github上有一个使用此解决方案的项目：https : //github.com/rstoyanchev/spring-mvc-31-demo/

和相关的SO问题：在Spring MVC 3.1中添加自定义RequestCondition

也许像@Subdomain("www")类型和方法这样的映射，可能的解决方案？

Answer 1

我已经创建了基于引用的spring-mvc-31-demo的解决方案

到目前为止，此解决方案只能用于映射单个RequestCondition。我创建了两个要通知的问题，应该对此进行更改：
https : //github.com/rstoyanchev/spring-mvc-31-demo/issues/5
https://jira.springsource.org/browse/SPR-9350

该解决方案使用Spring 3.1.1.RELEASE平台的自定义@RequestCondition功能

用法

范例1：

@Controller
@SubdomainMapping(value = "subdomain", tld = ".mydomain.com")
class MyController1 {
    // Code here will be executed only on address match:
    // subdomain.mydomain.com
}

范例2：

@Controller
class MyController2 {

    @RequestMapping("/index.html")
    @SubdomainMapping("www")
    public function index_www(Map<Object, String> map){
        // on www.domain.com
        // where ".domain.com" is defined in SubdomainMapping.java
    }

    @RequestMapping("/index.html")
    @SubdomainMapping("custom")
    public function index_custom(Map<Object, String> map){
        // on custom.domain.com
        // where ".domain.com" is defined in SubdomainMapping.java
    }
}

我们需要三个文件

• SubdomainMapping.java
• SubdomainRequestCondition.java
• SubdomainRequestMappingHandlerMapping.java

SubdomainMapping.java

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target({ElementType.METHOD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
public @interface SubdomainMapping {

    /**
    * This param defines single or multiple subdomain
    * Where the Method/Type is valid to be called
    */
    String[] value() default {};
    /**
    * This param defines site domain and tld
    * It's important to put the leading dot
    * Not an array, so cannot be used for mapping multiple domains/tld
    */
    String tld() default ".custom.tld";
}

SubdomainRequestCondition.java

import java.net.URL;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.Set;

import javax.servlet.http.HttpServletRequest;

import org.springframework.web.servlet.mvc.condition.RequestCondition;

public class SubdomainRequestCondition implements
        RequestCondition<SubdomainRequestCondition> {

    private final Set<String> subdomains;
    private final String tld;

    public SubdomainRequestCondition(String tld, String... subdomains) {
        this(tld, Arrays.asList(subdomains));
    }

    public SubdomainRequestCondition(String tld, Collection<String> subdomains) {
        this.subdomains = Collections.unmodifiableSet(new HashSet<String>(
                subdomains));
        this.tld = tld;
    }

    @Override
    public SubdomainRequestCondition combine(SubdomainRequestCondition other) {
        Set<String> allRoles = new LinkedHashSet<String>(this.subdomains);
        allRoles.addAll(other.subdomains);
        return new SubdomainRequestCondition(tld, allRoles);
    }

    @Override
    public SubdomainRequestCondition getMatchingCondition(
            HttpServletRequest request) {
        try {
            URL uri = new URL(request.getRequestURL().toString());
            String[] parts = uri.getHost().split(this.tld);
            if (parts.length == 1) {
                for (String s : this.subdomains) {
                    if (s.equalsIgnoreCase(parts[0])) {
                        return this;
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace(System.err);
        }
        return null;
    }

    @Override
    public int compareTo(SubdomainRequestCondition other,
            HttpServletRequest request) {
        return org.apache.commons.collections.CollectionUtils.removeAll(other.subdomains, this.subdomains).size();
    }

}

SubdomainRequestMappingHandlerMapping.java

import java.lang.reflect.Method;

import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.web.servlet.mvc.condition.RequestCondition;
import org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping;

public class CustomRequestMappingHandlerMapping extends
        RequestMappingHandlerMapping {

    @Override
    protected RequestCondition<?> getCustomTypeCondition(Class<?> handlerType) {
        SubdomainMapping typeAnnotation = AnnotationUtils.findAnnotation(
                handlerType, SubdomainMapping.class);
        return createCondition(typeAnnotation);
    }

    @Override
    protected RequestCondition<?> getCustomMethodCondition(Method method) {
        SubdomainMapping methodAnnotation = AnnotationUtils.findAnnotation(
                method, SubdomainMapping.class);
        return createCondition(methodAnnotation);
    }

    private RequestCondition<?> createCondition(SubdomainMapping accessMapping) {
        return (accessMapping != null) ? new SubdomainRequestCondition(
                accessMapping.tld(), accessMapping.value()) : null;
    }

}

安装方式

重要说明：到目前为止，无法将此解决方案与XML元素
一起使用，请参见JIRA https://jira.springsource.org/browse/SPR-9344以获取解释。

• 你必须注册自定义MappingHandler bean，指向此自定义实现SubdomainRequestMappingHandlerMapping类。
• 你必须将其订单设置为低于默认订单，RequestMappingHandlerMapping
  或
  替换已注册的RequestMappingHandlerMapping订单（可能在order = 0上）
  有关实现此解决方案的更多说明，请参见相关的github项目。