什么是CURD
CURD是一个数据库技术中的缩写词,一般的项目开发的各种参数的基本功能都是CURD。作用是用于处理数据的基本操作。它代表创建(Create)、更新(Update)、读取(Retrieve)和删除(Delete)操作。
第一步、在mango-common新建utils包
在包下创建ReflectionUtils.java
package com.louis.mango.common.utils;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
/**
* 反射相关辅助方法
* @author Louis
* @date Aug 19, 2018
*/
public class ReflectionUtils {
/**
* 根据方法名调用指定对象的方法
* @param object 要调用方法的对象
* @param method 要调用的方法名
* @param args 参数对象数组
* @return
*/
public static Object invoke(Object object, String method, Object... args) {
Object result = null;
Class<? extends Object> clazz = object.getClass();
Method queryMethod = getMethod(clazz, method, args);
if(queryMethod != null) {
try {
result = queryMethod.invoke(object, args);
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
} else {
try {
throw new NoSuchMethodException(clazz.getName() + " 类中没有找到 " + method + " 方法。");
} catch (NoSuchMethodException e) {
e.printStackTrace();
}
}
return result;
}
/**
* 根据方法名和参数对象查找方法
* @param clazz
* @param name
* @param args 参数实例数据
* @return
*/
public static Method getMethod(Class<? extends Object> clazz, String name, Object[] args) {
Method queryMethod = null;
Method[] methods = clazz.getMethods();
for(Method method:methods) {
if(method.getName().equals(name)) {
Class<?>[] parameterTypes = method.getParameterTypes();
if(parameterTypes.length == args.length) {
boolean isSameMethod = true;
for(int i=0; i<parameterTypes.length; i++) {
Object arg = args[i];
if(arg == null) {
arg = "";
}
if(!parameterTypes[i].equals(args[i].getClass())) {
isSameMethod = false;
}
}
if(isSameMethod) {
queryMethod = method;
break ;
}
}
}
}
return queryMethod;
}
}
第二步、在mango-core新建包
在server包下创建CurdService.java
import com.louis.mango.core.page.PageRequest;
import com.louis.mango.core.page.PageResult;
import java.util.List;
public interface CurdService<T> {
/**
* 保存
* @param record
* @return
*/
int Save(T record);
/**
* 删除操作
* @param record
* @return
*/
int delete(T record);
/**
* 批量删除
* @param record
* @return
*/
int delete(List<T> record);
/**
* 根据id查询
* @param id
* @return
*/
T findById(Long id);
PageResult findPage(PageRequest pageRequest);
}
在page下新增分页代码封装PageResult.java、PageRequest.java、MybatisPageHelper.java
分页助手封装类
在mango-core的pom.xml文件中新增Mybatis分页插件pagehelper
相关依赖
<!-- pagehelper -->
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper-spring-boot-starter</artifactId>
<version>1.3.0</version>
</dependency>
在mango-admin的yml配置文件中添加配置
pagehelper:
helperDialect: mysql
reasonable: true
supportMethodsArguments: true
params: count=countSql
在page包下创建MybatisPageHelper.java、PageRequest.java、PageResult.java分页类
MybatisPageHelper.java
package com.louis.mango.core.page;
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import com.louis.mango.common.utils.ReflectionUtils;
import java.util.List;
/**
* MyBatis 分页查询助手
* @author Louis
* @date Jan 12, 2019
*/
public class MybatisPageHelper {
public static final String findPage = "findPage";
/**
* 分页查询, 约定查询方法名为 “findPage”
* @param pageRequest 分页请求
* @param mapper Dao对象,MyBatis的 Mapper
* @param
* @return
*/
public static PageResult findPage(PageRequest pageRequest, Object mapper) {
return findPage(pageRequest, mapper, findPage);
}
/**
* 调用分页插件进行分页查询
* @param pageRequest 分页请求
* @param mapper Dao对象,MyBatis的 Mapper
* @param queryMethodName 要分页的查询方法名
* @param args 方法参数
* @return
*/
@SuppressWarnings({ "unchecked", "rawtypes" })
public static PageResult findPage(PageRequest pageRequest, Object mapper, String queryMethodName, Object... args) {
// 设置分页参数
int pageNum = pageRequest.getPageNum();
int pageSize = pageRequest.getPageSize();
PageHelper.startPage(pageNum, pageSize);
// 利用反射调用查询方法
Object result = ReflectionUtils.invoke(mapper, queryMethodName, args);
return getPageResult(pageRequest, new PageInfo((List) result));
}
/**
* 将分页信息封装到统一的接口
* @param pageRequest
* @param
* @return
*/
private static PageResult getPageResult(PageRequest pageRequest, PageInfo<?> pageInfo) {
PageResult pageResult = new PageResult();
pageResult.setPageNum(pageInfo.getPageNum());
pageResult.setPageSize(pageInfo.getPageSize());
pageResult.setTotalSize(pageInfo.getTotal());
pageResult.setTotalPages(pageInfo.getPages());
pageResult.setContent(pageInfo.getList());
return pageResult;
}
}
PageRequest.java
package com.louis.mango.core.page;
import java.util.HashMap;
import java.util.Map;
/**
* 分页请求分装类
*/
public class PageRequest {
/**
* 当前页码
*/
private int pageNum = 1;
/**
*每页数量
*/
private int pageSize = 10;
/**
* 查询参数
*/
private Map<String,Object> params = new HashMap<String,Object>();
public int getPageNum() {
return pageNum;
}
public void setPageNum(int pageNum) {
this.pageNum = pageNum;
}
public int getPageSize() {
return pageSize;
}
public void setPageSize(int pageSize) {
this.pageSize = pageSize;
}
public Map<String, Object> getParams() {
return params;
}
public void setParams(Map<String, Object> params) {
this.params = params;
}
}
PageResult.java
package com.louis.mango.core.page;
import java.util.List;
/**
* 分页结果封装类
*/
public class PageResult {
/**
* 当前页码
*/
private int pageNum;
/**
* 每页数量
*/
private int pageSize;
/**
* 记录总数
*/
private long totalSize;
/**
* 页码总数
*/
private int totalPages;
/**
* 分页数据
*/
private List<?> content;
public int getPageNum() {
return pageNum;
}
public void setPageNum(int pageNum) {
this.pageNum = pageNum;
}
public int getPageSize() {
return pageSize;
}
public void setPageSize(int pageSize) {
this.pageSize = pageSize;
}
public long getTotalSize() {
return totalSize;
}
public void setTotalSize(long totalSize) {
this.totalSize = totalSize;
}
public int getTotalPages() {
return totalPages;
}
public void setTotalPages(int totalPages) {
this.totalPages = totalPages;
}
public List<?> getContent() {
return content;
}
public void setContent(List<?> content) {
this.content = content;
}
}
在http包下新建 HttpResult.java、HttpStatus、java
对调用的结果进行统一封装返回给前端 HttpResult.java
package com.louis.mango.core.http;
/**
* HTTP结果封装
* @author Louis
* @date Jan 12, 2019
*/
public class HttpResult {
private int code = 200;
private String msg;
private Object data;
public static HttpResult error() {
return error(HttpStatus.SC_INTERNAL_SERVER_ERROR, "未知异常,请联系管理员");
}
public static HttpResult error(String msg) {
return error(HttpStatus.SC_INTERNAL_SERVER_ERROR, msg);
}
public static HttpResult error(int code, String msg) {
HttpResult r = new HttpResult();
r.setCode(code);
r.setMsg(msg);
return r;
}
public static HttpResult ok(String msg) {
HttpResult r = new HttpResult();
r.setMsg(msg);
return r;
}
public static HttpResult ok(Object data) {
HttpResult r = new HttpResult();
r.setData(data);
return r;
}
public static HttpResult ok() {
return new HttpResult();
}
public int getCode() {
return code;
}
public void setCode(int code) {
this.code = code;
}
public String getMsg() {
return msg;
}
public void setMsg(String msg) {
this.msg = msg;
}
public Object getData() {
return data;
}
public void setData(Object data) {
this.data = data;
}
}
HttpStatus.java
package com.louis.mango.core.http;
/**
* Constants enumerating the HTTP status codes.
* All status codes defined in RFC1945 (HTTP/1.0), RFC2616 (HTTP/1.1), and
* RFC2518 (WebDAV) are listed.
*
* @see
*
* @since 4.0
*/
public interface HttpStatus {
// --- 1xx Informational ---
/** {@code 100 Continue} (HTTP/1.1 - RFC 2616) */
public static final int SC_CONTINUE = 100;
/** {@code 101 Switching Protocols} (HTTP/1.1 - RFC 2616)*/
public static final int SC_SWITCHING_PROTOCOLS = 101;
/** {@code 102 Processing} (WebDAV - RFC 2518) */
public static final int SC_PROCESSING = 102;
// --- 2xx Success ---
/** {@code 200 OK} (HTTP/1.0 - RFC 1945) */
public static final int SC_OK = 200;
/** {@code 201 Created} (HTTP/1.0 - RFC 1945) */
public static final int SC_CREATED = 201;
/** {@code 202 Accepted} (HTTP/1.0 - RFC 1945) */
public static final int SC_ACCEPTED = 202;
/** {@code 203 Non Authoritative Information} (HTTP/1.1 - RFC 2616) */
public static final int SC_NON_AUTHORITATIVE_INFORMATION = 203;
/** {@code 204 No Content} (HTTP/1.0 - RFC 1945) */
public static final int SC_NO_CONTENT = 204;
/** {@code 205 Reset Content} (HTTP/1.1 - RFC 2616) */
public static final int SC_RESET_CONTENT = 205;
/** {@code 206 Partial Content} (HTTP/1.1 - RFC 2616) */
public static final int SC_PARTIAL_CONTENT = 206;
/**
* {@code 207 Multi-Status} (WebDAV - RFC 2518)
* or
* {@code 207 Partial Update OK} (HTTP/1.1 - draft-ietf-http-v11-spec-rev-01?)
*/
public static final int SC_MULTI_STATUS = 207;
// --- 3xx Redirection ---
/** {@code 300 Mutliple Choices} (HTTP/1.1 - RFC 2616) */
public static final int SC_MULTIPLE_CHOICES = 300;
/** {@code 301 Moved Permanently} (HTTP/1.0 - RFC 1945) */
public static final int SC_MOVED_PERMANENTLY = 301;
/** {@code 302 Moved Temporarily} (Sometimes {@code Found}) (HTTP/1.0 - RFC 1945) */
public static final int SC_MOVED_TEMPORARILY = 302;
/** {@code 303 See Other} (HTTP/1.1 - RFC 2616) */
public static final int SC_SEE_OTHER = 303;
/** {@code 304 Not Modified} (HTTP/1.0 - RFC 1945) */
public static final int SC_NOT_MODIFIED = 304;
/** {@code 305 Use Proxy} (HTTP/1.1 - RFC 2616) */
public static final int SC_USE_PROXY = 305;
/** {@code 307 Temporary Redirect} (HTTP/1.1 - RFC 2616) */
public static final int SC_TEMPORARY_REDIRECT = 307;
// --- 4xx Client Error ---
/** {@code 400 Bad Request} (HTTP/1.1 - RFC 2616) */
public static final int SC_BAD_REQUEST = 400;
/** {@code 401 Unauthorized} (HTTP/1.0 - RFC 1945) */
public static final int SC_UNAUTHORIZED = 401;
/** {@code 402 Payment Required} (HTTP/1.1 - RFC 2616) */
public static final int SC_PAYMENT_REQUIRED = 402;
/** {@code 403 Forbidden} (HTTP/1.0 - RFC 1945) */
public static final int SC_FORBIDDEN = 403;
/** {@code 404 Not Found} (HTTP/1.0 - RFC 1945) */
public static final int SC_NOT_FOUND = 404;
/** {@code 405 Method Not Allowed} (HTTP/1.1 - RFC 2616) */
public static final int SC_METHOD_NOT_ALLOWED = 405;
/** {@code 406 Not Acceptable} (HTTP/1.1 - RFC 2616) */
public static final int SC_NOT_ACCEPTABLE = 406;
/** {@code 407 Proxy Authentication Required} (HTTP/1.1 - RFC 2616)*/
public static final int SC_PROXY_AUTHENTICATION_REQUIRED = 407;
/** {@code 408 Request Timeout} (HTTP/1.1 - RFC 2616) */
public static final int SC_REQUEST_TIMEOUT = 408;
/** {@code 409 Conflict} (HTTP/1.1 - RFC 2616) */
public static final int SC_CONFLICT = 409;
/** {@code 410 Gone} (HTTP/1.1 - RFC 2616) */
public static final int SC_GONE = 410;
/** {@code 411 Length Required} (HTTP/1.1 - RFC 2616) */
public static final int SC_LENGTH_REQUIRED = 411;
/** {@code 412 Precondition Failed} (HTTP/1.1 - RFC 2616) */
public static final int SC_PRECONDITION_FAILED = 412;
/** {@code 413 Request Entity Too Large} (HTTP/1.1 - RFC 2616) */
public static final int SC_REQUEST_TOO_LONG = 413;
/** {@code 414 Request-URI Too Long} (HTTP/1.1 - RFC 2616) */
public static final int SC_REQUEST_URI_TOO_LONG = 414;
/** {@code 415 Unsupported Media Type} (HTTP/1.1 - RFC 2616) */
public static final int SC_UNSUPPORTED_MEDIA_TYPE = 415;
/** {@code 416 Requested Range Not Satisfiable} (HTTP/1.1 - RFC 2616) */
public static final int SC_REQUESTED_RANGE_NOT_SATISFIABLE = 416;
/** {@code 417 Expectation Failed} (HTTP/1.1 - RFC 2616) */
public static final int SC_EXPECTATION_FAILED = 417;
/**
* Static constant for a 418 error.
* {@code 418 Unprocessable Entity} (WebDAV drafts?)
* or {@code 418 Reauthentication Required} (HTTP/1.1 drafts?)
*/
// not used
// public static final int SC_UNPROCESSABLE_ENTITY = 418;
/**
* Static constant for a 419 error.
* {@code 419 Insufficient Space on Resource}
* (WebDAV - draft-ietf-webdav-protocol-05?)
* or {@code 419 Proxy Reauthentication Required}
* (HTTP/1.1 drafts?)
*/
public static final int SC_INSUFFICIENT_SPACE_ON_RESOURCE = 419;
/**
* Static constant for a 420 error.
* {@code 420 Method Failure}
* (WebDAV - draft-ietf-webdav-protocol-05?)
*/
public static final int SC_METHOD_FAILURE = 420;
/** {@code 422 Unprocessable Entity} (WebDAV - RFC 2518) */
public static final int SC_UNPROCESSABLE_ENTITY = 422;
/** {@code 423 Locked} (WebDAV - RFC 2518) */
public static final int SC_LOCKED = 423;
/** {@code 424 Failed Dependency} (WebDAV - RFC 2518) */
public static final int SC_FAILED_DEPENDENCY = 424;
// --- 5xx Server Error ---
/** {@code 500 Server Error} (HTTP/1.0 - RFC 1945) */
public static final int SC_INTERNAL_SERVER_ERROR = 500;
/** {@code 501 Not Implemented} (HTTP/1.0 - RFC 1945) */
public static final int SC_NOT_IMPLEMENTED = 501;
/** {@code 502 Bad Gateway} (HTTP/1.0 - RFC 1945) */
public static final int SC_BAD_GATEWAY = 502;
/** {@code 503 Service Unavailable} (HTTP/1.0 - RFC 1945) */
public static final int SC_SERVICE_UNAVAILABLE = 503;
/** {@code 504 Gateway Timeout} (HTTP/1.1 - RFC 2616) */
public static final int SC_GATEWAY_TIMEOUT = 504;
/** {@code 505 HTTP Version Not Supported} (HTTP/1.1 - RFC 2616) */
public static final int SC_HTTP_VERSION_NOT_SUPPORTED = 505;
/** {@code 507 Insufficient Storage} (WebDAV - RFC 2518) */
public static final int SC_INSUFFICIENT_STORAGE = 507;
}
第三步、配置sql
在SysUserMapper.xml中添加分页查询方法
<select id="findPage" resultMap="BaseResultMap">
select <include refid="Base_Column_List"/>
from sys_user
</select>
第四步、配置Sercice层
让SysUserService继承CurdService,并增加查询方法
public interface SysUserService extends CurdService<SysUser> {
/**
* 查找所有用户
* @return
*/
List<SysUser> findAll();
}
在serviceImpl中是实现相关方法,我们这里以分页查询为例
@Service
public class SysUserServiceImpl implements SysUserService {
@Autowired
private SysUserMapper sysUserMapper;
@Override
public List<SysUser> findAll() {
return sysUserMapper.findAll();
}
@Override public PageResult findPage(PageRequest pageRequest) {
return MybatisPageHelper.findPage(pageRequest,sysUserMapper);
}
@Override
public int Save(SysUser record) {
return 0;
}
@Override
public int delete(SysUser record) {
return 0;
}
@Override
public int delete(List<SysUser> record) {
return 0;
}
@Override
public SysUser findById(Long id) {
return null;
}
}
第五步、配置Dao层
@Repository
public interface SysUserMapper {
/**
* 查询全部
* @return
*/
List<SysUser> findAll();
/**
* 分页查询
*/
List<SysUser> findPage();
int deleteByPrimaryKey(Long id);
int insert(SysUser record);
int insertSelective(SysUser record);
SysUser selectByPrimaryKey(Long id);
int updateByPrimaryKeySelective(SysUser record);
int updateByPrimaryKey(SysUser record);
}
第六步、配置controller
@RestController
@RequestMapping("user")
public class SysUserController {
@Autowired
private SysUserService sysUserService;
@GetMapping(value="/findAll")
public Object findAll() {
return sysUserService.findAll();
}
@PostMapping(value = "/findPage")
public HttpResult findPage(@RequestBody PageRequest pageRequest){
return HttpResult.ok(sysUserService.findPage(pageRequest));
}
}
到此我们已经完成了CURD的通用接口,然后启动项目,访问swagger 进行测试
http://localhost:8001/swagger-ui.html#/
响应结果
如图,已经成功