junit4单元测试

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>cn.idea360</groupId>
    <artifactId>junit-demo</artifactId>
    <version>1.0.0</version>

    <name>junit-demo</name>
    <description>junit4 mock测试. 欢迎关注公众号【当我遇上你】</description>

    <properties>
        <maven.compiler.source>11</maven.compiler.source>
        <maven.compiler.target>11</maven.compiler.target>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.26</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>4.0.1</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-simple</artifactId>
            <version>1.7.32</version>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.mockito</groupId>
            <artifactId>mockito-core</artifactId>
            <version>5.2.0</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13.2</version>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>commons-io</groupId>
            <artifactId>commons-io</artifactId>
            <version>2.11.0</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.14.2</version>
        </dependency>
    </dependencies>
</project>

过滤器实现

package cn.idea360.junit.filter;

import cn.idea360.junit.wrapper.ContentCachingRequestWrapper;
import com.fasterxml.jackson.databind.ObjectMapper;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.io.IOUtils;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.nio.charset.StandardCharsets;
import java.util.HashMap;
import java.util.Map;

/**
 * @author cuishiying
 */
@Slf4j
public class LogFilter implements Filter{

    private final ObjectMapper objectMapper = new ObjectMapper();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        ContentCachingRequestWrapper request = new ContentCachingRequestWrapper((HttpServletRequest) servletRequest);
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        // 请求头
        String header = request.getHeader("blog");
        // 整个URL的路径
        String requestURL = request.getRequestURL().toString();
        // 上下文路径(工程名)
        String contextPath = request.getContextPath();
        // 除去host和工程名部分的路径
        String servletPath = request.getServletPath();
        // 除去host部分的路径
        String requestURI = request.getRequestURI();
        // 请求类型
        String method = request.getMethod();
        // urlParams, 即?后的字符串则为其请求参数，并以&作为分隔符
        String queryString = request.getQueryString();
        // 默认content-type为application/x-www-form-urlencoded, 参数会以Form Data的形式进行传递，不会显式出现在请求url中
        Map<String, String[]> parameterMap = request.getParameterMap();
        // 请求体
        String body = IOUtils.toString(request.getInputStream(), StandardCharsets.UTF_8);
        log.info(body);
        filterChain.doFilter(request, response);
        sendUnauthorizedMessage(response, "验签失败");
    }

    private void sendUnauthorizedMessage(HttpServletResponse response, String message) {
        response.setContentType("application/json;charset=UTF-8");
        response.setCharacterEncoding(StandardCharsets.UTF_8.name());
        response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);

        try {
            PrintWriter out = response.getWriter();
            Map<String,Object> map = new HashMap<>();
            map.put("code", HttpServletResponse.SC_UNAUTHORIZED);
            map.put("msg", message);
            out.write(objectMapper.writeValueAsString(map));
            out.flush();
            out.close();
        } catch (Exception e) {
            log.error("can't push signature err message", e);
        }
    }
}

ServletInputStream抽象类实现

package cn.idea360.junit.delegate;

import org.junit.Assert;

import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 * @see org.springframework.mock.web.DelegatingServletInputStream
 *
 * @author cuishiying
 */
public class DelegatingServletInputStream extends ServletInputStream {

    private final InputStream sourceStream;

    private boolean finished = false;


    /**
     * Create a DelegatingServletInputStream for the given source stream.
     * @param sourceStream the source stream (never {@code null})
     */
    public DelegatingServletInputStream(InputStream sourceStream) {
        Assert.assertNotNull("Source InputStream must not be null", sourceStream);
        this.sourceStream = sourceStream;
    }

    /**
     * Return the underlying source stream (never {@code null}).
     */
    public final InputStream getSourceStream() {
        return this.sourceStream;
    }


    @Override
    public int read() throws IOException {
        int data = this.sourceStream.read();
        if (data == -1) {
            this.finished = true;
        }
        return data;
    }

    @Override
    public int available() throws IOException {
        return this.sourceStream.available();
    }

    @Override
    public void close() throws IOException {
        super.close();
        this.sourceStream.close();
    }

    @Override
    public boolean isFinished() {
        return this.finished;
    }

    @Override
    public boolean isReady() {
        return true;
    }

    @Override
    public void setReadListener(ReadListener readListener) {
        throw new UnsupportedOperationException();
    }

}

流重复消费处理

package cn.idea360.junit.wrapper;

import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.*;

/**
 * @author cuishiying
 */
public class ContentCachingRequestWrapper extends HttpServletRequestWrapper {

    private final byte[] buffer;

    public ContentCachingRequestWrapper(HttpServletRequest request) throws IOException {
        super(request);
        InputStream is = request.getInputStream();
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        byte[] buff = new byte[1024];
        int read;
        while ((read = is.read(buff)) > 0) {
            baos.write(buff, 0, read);
        }
        this.buffer = baos.toByteArray();
    }

    @Override
    public ServletInputStream getInputStream() {
        final ByteArrayInputStream bais = new ByteArrayInputStream(buffer);
        return new ServletInputStream() {

            @Override
            public boolean isFinished() {
                return false;
            }

            @Override
            public boolean isReady() {
                return false;
            }

            @Override
            public void setReadListener(ReadListener readListener) {
                // document why this method is empty
            }

            @Override
            public int read() {
                return bais.read();
            }
        };
    }

    @Override
    public BufferedReader getReader() throws IOException {
        return new BufferedReader(new InputStreamReader(getInputStream()));
    }
}

Mock测试

package cn.idea360.junit.filter;

import cn.idea360.junit.delegate.DelegatingServletInputStream;
import lombok.extern.slf4j.Slf4j;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.junit.MockitoJUnitRunner;

import javax.servlet.FilterChain;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.ByteArrayInputStream;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.nio.charset.StandardCharsets;

import static org.mockito.Mockito.*;

@Slf4j
@RunWith(MockitoJUnitRunner.class)
public class LogFilterTest {

    private StringWriter writer;

    @Before
    public void setUp() throws Exception {
        writer = new StringWriter();
    }

    @Test
    public void logFilter() throws Exception {
        HttpServletRequest request = mock(HttpServletRequest.class);
        HttpServletResponse response = mock(HttpServletResponse.class);
        FilterChain filterChain = mock(FilterChain.class);

        String requestBody = "{\"msg\": \"Hello World\"}";

        when(request.getHeader("blog")).thenReturn("idea360.cn");
        when(request.getMethod()).thenReturn("POST");
        when(request.getRequestURL()).thenReturn(new StringBuffer("http://localhost:8080/junit-demo/sign"));
        when(request.getContextPath()).thenReturn("/junit-demo");
        when(request.getServletPath()).thenReturn("/sign");
        when(request.getRequestURI()).thenReturn("/junit-demo/sign");
        when(request.getCharacterEncoding()).thenReturn(StandardCharsets.UTF_8.name());
        when(request.getContentType()).thenReturn("application/json");
        when(request.getParameter("age")).thenReturn("17");
        when(request.getQueryString()).thenReturn("name=admin");
        when(request.getInputStream()).thenReturn(new DelegatingServletInputStream(new ByteArrayInputStream(requestBody.getBytes(StandardCharsets.UTF_8))));

        when(response.getWriter()).thenReturn(new PrintWriter(writer));

        LogFilter filter = new LogFilter();
        filter.doFilter(request, response, filterChain);

        Assert.assertEquals("{\"msg\":\"验签失败\",\"code\":401}", writer.toString());
    }
}