为spring get请求添加自定义的参数处理操作(如下划线转驼峰)

1.生成自己的注解（为了确定在哪些位置使用）

/**
* 关闭patch delete的model处理，否则会报错
*/
@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface AliasProcessor {
}

/**
* 处理Get 请求参数的驼峰问题
* @author lw
*/
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface ValueFrom {
/**
* 参数名(别名)列表
*/
String[] value();
}

2.实现自己的ServletModelAttributeMethodProcessor

/**
* 为了减少使用 @RequestPath 将get参数封装到实体类中 重写ModelAttributeMethodProcessor
* 注：由于get请求为非raw请求，spring默认使用@ModelArrtribute注解，不会自动将下划线的数据转为驼峰数据
* 所以需要自定义一个处理器，进行该操作 *
* @author lw
*/

public class AliasModelAttributeMethodProcessor extends ServletModelAttributeMethodProcessor {
private ApplicationContext applicationContext;

/**
* 过滤掉patch请求，防止报错
*/
@Override
public boolean supportsParameter(MethodParameter parameter) {
return parameter.getMethodAnnotation(AliasProcessor.class)!=null;
}

public AliasModelAttributeMethodProcessor(ApplicationContext applicationContext) {
super(true);
this.applicationContext=applicationContext;
}

@Override
protected void bindRequestParameters(WebDataBinder binder, NativeWebRequest request) {
AliasDataBinder aliasBinder = new AliasDataBinder(binder.getTarget(), binder.getObjectName());
RequestMappingHandlerAdapter requestMappingHandlerAdapter = this.applicationContext.getBean(RequestMappingHandlerAdapter.class);
requestMappingHandlerAdapter.getWebBindingInitializer().initBinder(aliasBinder);
aliasBinder.bind(request.getNativeRequest(ServletRequest.class));
}
}

3.自己的数据处理类

/**
* 重新数据处理类
* @author lw
*/
public class AliasDataBinder extends ExtendedServletRequestDataBinder {

public AliasDataBinder(Object target, String objectName) {
super(target, objectName);
}

/**
* 复写addBindValues方法
* @param mpvs 这里面存的就是请求参数的key-value对
* @param request 请求本身, 这里没有用到
*/
@Override
protected void addBindValues(MutablePropertyValues mpvs, ServletRequest request) {
super.addBindValues(mpvs, request);
// 处理要绑定参数的对象
Class<?> targetClass = getTarget().getClass();
// 获取对象的所有字段(拿到Test类的字段)
Field[] fields = targetClass.getDeclaredFields();
// 处理所有字段
for (Field field : fields) {
 // 原始字段上的注解
 ValueFrom valueFromAnnotation = field.getAnnotation(ValueFrom.class);
 // 若参数中包含原始字段或者字段没有别名注解, 则跳过该字段
 if (mpvs.contains(field.getName()) || valueFromAnnotation == null) {
 continue;
 }
 // 参数中没有原始字段且字段上有别名注解, 则依次取别名列表中的别名, 在参数中最先找到的别名的值赋值给原始字段
 for (String alias : valueFromAnnotation.value()) {
 // 若参数中包含该别名, 则把别名的值赋值给原始字段
 if (mpvs.contains(alias)) {
  // 给原始字段赋值
  mpvs.add(field.getName(), mpvs.getPropertyValue(alias).getValue());
  // 跳出循环防止取其它别名
  break;
 }
 }
}
}
}

4.注册到spring中

/**
* 为了获得context需要实现ApplicationContextAware接口
* @author lw
*/
@Configuration
public class WebmvcConfig implements ApplicationContextAware {

@Autowired
private RequestMappingHandlerAdapter adapter;

private ApplicationContext applicationContext = null;

@Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
this.applicationContext=applicationContext;
}

/**
* 将自定义的processor添加到adapter中
*/
@PostConstruct
protected void injectSelfMethodArgumentResolver() {
List<HandlerMethodArgumentResolver> argumentResolvers = new ArrayList<>();
argumentResolvers.add(new AliasModelAttributeMethodProcessor(this.applicationContext));
argumentResolvers.addAll(adapter.getArgumentResolvers());
adapter.setArgumentResolvers(argumentResolvers);
}
}

补充知识：springboot - mybatis - 下划线与驼峰自动转换 mapUnderscoreToCamelCase

以前都是在mybatis.xml中来配置，但是spring boot不想再用xml配置文件。网上搜寻了好久，才找到设置办法：

sessionFactoryBean.getObject().getConfiguration().setMapUnderscoreToCamelCase(true);

db配置文件源码：

package com.vip.qa.vop.config;

import com.alibaba.druid.pool.DruidDataSource;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import javax.sql.DataSource;
import java.util.Properties;

/**
* Created by danny.yao on 2017/10/25.
*/
@Configuration
@MapperScan(basePackages = VOPDataSourceConfig.PACKAGE, sqlSessionFactoryRef = "vopSqlSessionFactory")
public class VOPDataSourceConfig {
static final String PACKAGE = "com.vip.qa.vop.mapper.vop";

@Value("${vop.datasource.url}")
private String dbUrl;

@Value("${vop.datasource.username}")
private String dbUser;

@Value("${vop.datasource.password}")
private String dbPassword;

@Value("${vop.datasource.driver-class-name}")
private String dbDriver;

@Bean(name = "vopDataSource")
@Qualifier
@Primary
public DataSource vopDataSource() {
DruidDataSource dataSource = new DruidDataSource();
dataSource.setDriverClassName(dbDriver);
dataSource.setUrl(dbUrl);
dataSource.setUsername(dbUser);
dataSource.setPassword(dbPassword);
return dataSource;
}

@Bean(name = "vopSqlSessionFactory")
@Qualifier
@Primary
public SqlSessionFactory vopSqlSessionFactory(@Qualifier("vopDataSource") DataSource scepDataSource) throws Exception {
final SqlSessionFactoryBean sessionFactoryBean = new SqlSessionFactoryBean();
sessionFactoryBean.setDataSource(scepDataSource);

PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
sessionFactoryBean.setMapperLocations(resolver.getResources("classpath:/mybatis/vop/*.xml"));
sessionFactoryBean.getObject().getConfiguration().setMapUnderscoreToCamelCase(true);

return sessionFactoryBean.getObject();
}

// @Bean(name = "vopTransactionManager")
// @Qualifier
// public DataSourceTransactionManager testDataTransactionManager() {
// return new DataSourceTransactionManager(vopDataSource());
// }

}

来源：https://blog.csdn.net/qq_36752632/article/details/90665221