Spring 引导补丁 MongoDB

Question

{
        "id": "5e6a5f98003bb209b536a1be",
        "firstName": "Alice",
        "lastName": "Smith"
    }



@Document
public class Customer {

    @Id
    public String id;

    public String firstName;
    public String lastName;

    public Customer() {}

    public Customer(String firstName, String lastName) {
        this.firstName = firstName;
        this.lastName = lastName;
    }

    @Override
    public String toString() {
        return String.format(
                "Customer[id=%s, firstName='%s', lastName='%s']",
                id, firstName, lastName);
    }

    public String getId() {
        return id;
    }

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

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

}

如果我尝试仅更新下面的姓氏 JSON body- firstName 将设置为 NULL ..我如何避免这种情况？那就是..只更新请求正文中的内容..不要将缺失的属性设置为空。

我正在使用 @PatchMapping("/customer/update")

{
        "id": "5e6a5f98003bb209b536a1be",
        "lastName": "Smith1"
    }

Answer 1

import java.io.IOException;
import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.core.MethodParameter;
import org.springframework.http.HttpInputMessage;
import org.springframework.http.converter.HttpMessageNotReadableException;
import org.springframework.http.server.ServletServerHttpRequest;
import org.springframework.stereotype.Component;
import org.springframework.util.ReflectionUtils;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.support.WebDataBinderFactory;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.method.support.ModelAndViewContainer;
import org.springframework.web.servlet.HandlerMapping;

import com.fasterxml.jackson.dataformat.xml.XmlMapper;

@Component
public class PartialUpdateArgumentResolver implements HandlerMethodArgumentResolver {

    XmlMapper xmlMapper= new XmlMapper();
    @Autowired ApplicationContext context;

    @Override
    public boolean supportsParameter(MethodParameter parameter) {
        RequestMapping methodAnot = parameter.getMethodAnnotation(RequestMapping.class);
        if( methodAnot == null ) return false;

        if( !Arrays.asList(methodAnot.method()).contains(RequestMethod.PATCH) ) return false;

        return parameter.hasParameterAnnotation(PatchRequestBody.class);
    }

    @Override
    public Object resolveArgument(MethodParameter parameter,
                                  ModelAndViewContainer mavContainer,
                                  NativeWebRequest webRequest,
                                  WebDataBinderFactory binderFactory) throws Exception {

        ServletServerHttpRequest req = createInputMessage(webRequest);

        Patch patch = parameter.getMethodAnnotation(Patch.class);
        Class serviceClass = patch.service();
        Class idClass = patch.id();
        Object service = context.getBean(serviceClass);

        String idStr = getPathVariables(webRequest).get("id");
        Object id = idClass.cast(idStr);
        Method method = ReflectionUtils.findMethod(serviceClass, "find", idClass);

        Object obj = ReflectionUtils.invokeMethod(method, service, id);
        obj = readJavaType(obj, req);
        return obj;
    }

    private Map<String, String> getPathVariables(NativeWebRequest webRequest) {

        HttpServletRequest httpServletRequest = webRequest.getNativeRequest(HttpServletRequest.class);
        return (Map<String, String>) httpServletRequest.getAttribute(HandlerMapping.URI_TEMPLATE_VARIABLES_ATTRIBUTE);
    }

    protected ServletServerHttpRequest createInputMessage(NativeWebRequest webRequest) {
        HttpServletRequest servletRequest = webRequest.getNativeRequest(HttpServletRequest.class);
        return new ServletServerHttpRequest(servletRequest);
    }

    private Object readJavaType(Object object, HttpInputMessage inputMessage) {
        try {
            return this.xmlMapper.readerForUpdating(object).readValue(inputMessage.getBody());
        }
        catch (IOException ex) {
            throw new HttpMessageNotReadableException("Could not read document: " + ex.getMessage(), ex);
        }
    }
}

Spring 引导补丁 MongoDB

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spring-boot