最近的工作上面需要用到这个功能，就查了下资料，问了下同学，找到了一篇文章（https://www.jb51.net/article/236923.htm），参考了一下。这里记录一下自己的做法，并且把一些问题记录下来。
思路：让前端把租户code放到请求头里面，我们做拦截，然后把该租户code放到本地线程（ThreadLocal）里面，再去执行业务方法。执行完之后再销毁本地线程。
问题1.最开始也是做的过滤器写的拦截器，但是遇到了swagger打不开，前端看不了接口的情况，所以后面又改成了拦截器写的。
问题2.遇到了流关闭的问题（Bad Request: I/O error while reading input message; nested exception is java），解决方式是重写一下。
问题3.Long类型返回进位问题（1524695643531628546 ->1524695643531628500）
问题4.前端组件多余字段过滤问题。
下面贴代码：
1.RequestWrapper
import com.alibaba.fastjson.JSONObject;
import org.apache.commons.codec.Charsets;
import org.apache.commons.lang3.StringUtils;
import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.*;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
public class RequestWrapper extends HttpServletRequestWrapper {
private String body;
public RequestWrapper(HttpServletRequest request) throws IOException {
super(request);
StringBuilder stringBuilder = new StringBuilder();
BufferedReader bufferedReader = null;
try {
InputStream inputStream = request.getInputStream();
if (inputStream != null) {
bufferedReader = new BufferedReader(new InputStreamReader(inputStream,"UTF-8"));
char[] charBuffer = new char[128];
int bytesRead = -1;
while ((bytesRead = bufferedReader.read(charBuffer)) > 0) {
stringBuilder.append(charBuffer, 0, bytesRead);
}
} else {
stringBuilder.append("");
}
} catch (IOException ex) {
throw ex;
} finally {
if (bufferedReader != null) {
try {
bufferedReader.close();
} catch (IOException ex) {
throw ex;
}
}
}
body = stringBuilder.toString();
}
@Override
public ServletInputStream getInputStream() throws IOException {
final ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(body.getBytes("UTF-8"));
ServletInputStream servletInputStream = new ServletInputStream() {
@Override
public boolean isFinished() {
return false;
}
@Override
public boolean isReady() {
return false;
}
@Override
public void setReadListener(ReadListener readListener) {
}
@Override
public int read() throws IOException {
return byteArrayInputStream.read();
}
};
return servletInputStream;
}
@Override
public BufferedReader getReader() throws IOException {
return new BufferedReader(new InputStreamReader(this.getInputStream(), Charsets.UTF_8));
}
public String getBody() {
return this.body;
}
@Override
public String getParameter(String name) {
return super.getParameter(name);
}
@Override
public Map getParameterMap() {
return super.getParameterMap();
}
@Override
public Enumeration getParameterNames() {
return super.getParameterNames();
}
@Override
public String[] getParameterValues(String name) {
return super.getParameterValues(name);
}
public void setParamsMaps(Map paramMaps) {
Map paramBodyMap = new HashMap();
if (!StringUtils.isEmpty(body)) {
paramBodyMap = JSONObject.parseObject(body, Map.class);
}
paramBodyMap.putAll(paramMaps);
body = JSONObject.toJSONString(paramBodyMap);
}
}
2.LogHttpServletRequestWrapper （）
import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.*;
public class LogHttpServletRequestWrapper extends HttpServletRequestWrapper {
private final String body;
public LogHttpServletRequestWrapper(HttpServletRequest request) {
super(request);
StringBuilder stringBuilder = new StringBuilder();
BufferedReader bufferedReader = null;
InputStream inputStream = null;
try {
inputStream = request.getInputStream();
if (inputStream != null) {
bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
char[] charBuffer = new char[128];
int bytesRead = -1;
while ((bytesRead = bufferedReader.read(charBuffer)) > 0) {
stringBuilder.append(charBuffer, 0, bytesRead);
}
} else {
stringBuilder.append("");
}
} catch (IOException ex) {
} finally {
if (inputStream != null) {
try {
inputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (bufferedReader != null) {
try {
bufferedReader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
body = stringBuilder.toString();
}
@Override
public ServletInputStream getInputStream() throws IOException {
final ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(body.getBytes());
ServletInputStream servletInputStream = new ServletInputStream() {
@Override
public boolean isFinished() {
return false;
}
@Override
public boolean isReady() {
return false;
}
@Override
public void setReadListener(ReadListener readListener) {
}
@Override
public int read() throws IOException {
return byteArrayInputStream.read();
}
};
return servletInputStream;
}
@Override
public BufferedReader getReader() throws IOException {
return new BufferedReader(new InputStreamReader(this.getInputStream()));
}
public String getBody() {
return this.body;
}
}
3.TenantFilter 过滤器（这里可以预留出来，后面做跨域等一些问题的解决）
import org.springframework.stereotype.Component;
import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
@Component
public class TenantFilter implements Filter {
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
//流读过一次就关闭了,想要读取第二次就重新赋值
LogHttpServletRequestWrapper req = new LogHttpServletRequestWrapper((HttpServletRequest) servletRequest);
RequestWrapper requestWrapper = new RequestWrapper(req);
filterChain.doFilter(requestWrapper, servletResponse);
}
}
4.TenantInterceptor 拦截器（同时把无效的请求来源等一些打印出来）
import cn.hutool.extra.servlet.ServletUtil;
import cn.hutool.json.JSONUtil;
import cn.hutool.log.StaticLog;
import org.apache.commons.lang3.StringUtils;
import org.springframework.lang.Nullable;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@Component
public class TenantInterceptor implements HandlerInterceptor {
public static ThreadLocal SCHEMA_LOCAL = new ThreadLocal<>();
public static String getSchema() {
String schema = SCHEMA_LOCAL.get();
if (StringUtils.isNotEmpty(schema)) {
return schema;
}
return "BASE";
}
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
LogHttpServletRequestWrapper req = new LogHttpServletRequestWrapper(request);
//获取租户code
String tenantCode = req.getHeader("tenantCode");
if (StringUtils.isEmpty(tenantCode)) {
//封装log实体类
StaticLog.info("请求来源： =》{}", req.getRemoteAddr());
StaticLog.info("请求URI：{}", req.getRequestURI());
StaticLog.info("请求方式：{}", req.getMethod());
StaticLog.info("请求失败原因：{}", "没有租户code");
if ("GET".equals(req.getMethod())) {
StaticLog.info("请求参数：{}", JSONUtil.parseObj(ServletUtil.getParams(req)));
} else {
String substring = req.getBody().substring(0, 1);
if ("{".equals(substring)) {
StaticLog.info("请求参数：{}", JSONUtil.parseObj(req.getBody()));
}
if ("[".equals(substring)) {
StaticLog.info("请求参数：{}", JSONUtil.parseArray(req.getBody()));
}
}
return false;
}
SCHEMA_LOCAL.set(tenantCode);
return true;
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable Exception ex) throws Exception {
//请求完了销毁本地线程
SCHEMA_LOCAL.remove();
}
}
5.WebMvcConfig(放行swagger，过滤重定向，前端组件多余字段以及进位问题)
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.module.SimpleModule;
import com.fasterxml.jackson.databind.ser.std.ToStringSerializer;
import com.xxx.xxx.config.interceptor.TenantInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.web.servlet.config.annotation.*;
import java.util.List;
@Configuration
public class WebMvcConfig extends WebMvcConfigurationSupport {
@Bean
public WebMvcConfigurer webMvcConfigurer() {
return new WebMvcConfigurer() {
//配置跨域
@Override
public void addCorsMappings(CorsRegistry registry) {
registry.addMapping("
SimpleModule simpleModule = new SimpleModule();
simpleModule.addSerializer(Long.class, ToStringSerializer.instance);
simpleModule.addSerializer(Long.TYPE, ToStringSerializer.instance);
//忽略前端组件多余的字段
objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES,false);
objectMapper.registerModule(simpleModule);
jackson2HttpMessageConverter.setObjectMapper(objectMapper);
converters.add(jackson2HttpMessageConverter);
}
6.一些pom
2.MybatisPlus的多租户配置cn.hutool hutool-all5.3.10 com.alibaba fastjson1.2.47
在网上搜索了一下原理，是在预编译层的时候做了拦截，把租户code塞进了sql语句里面，所以这里基本上每张表都要加租户code这个字段。（我这里的字段是tenant_code/tenantCode，另外项目用到的数据库为pgsql）。
1.配置文件
import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.autoconfigure.ConfigurationCustomizer;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.handler.TenantLineHandler;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.TenantLineInnerInterceptor;
import com.xxx.xxx.config.interceptor.TenantInterceptor;
import net.sf.jsqlparser.expression.Expression;
import net.sf.jsqlparser.expression.StringValue;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.transaction.annotation.EnableTransactionManagement;
@EnableTransactionManagement(proxyTargetClass = true)
@Configuration
public class MybatisPlusConfig {
@Bean
public MybatisPlusInterceptor mybatisPlusInterceptor() {
MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
interceptor.addInnerInterceptor(new TenantLineInnerInterceptor(new TenantLineHandler() {
//字段类型
@Override
public Expression getTenantId() {
String tenantCode = TenantInterceptor.getSchema();
return new StringValue(tenantCode);
}
//数据库字段名
@Override
public String getTenantIdColumn() {
return "tenant_code";
}
// 这是 default 方法,默认返回 false 表示所有表都需要拼多租户条件
@Override
public boolean ignoreTable(String tableName) {
return false;
}
}));
// 如果用了分页插件注意先 add TenantLineInnerInterceptor 再 add PaginationInnerInterceptor
// 用了分页插件必须设置 MybatisConfiguration#useDeprecatedExecutor = false
//TODO 这里用的pgsql 所以这里做了配置项
interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.POSTGRE_SQL));
return interceptor;
}
@Bean
public ConfigurationCustomizer configurationCustomizer() {
return configuration -> configuration.setUseDeprecatedExecutor(false);
}
}
2.pom
com.baomidou
mybatis-plus-boot-starter
3.2.0
另外如果有sql不需要用租户区分，那么在Mapper层/dao层的方法上面加上注解@InterceptorIgnore(tenantLine = "true")就好了，（有的网上说加@SqlParser(filter = true)也行但是我没有测试）
