Java HTTP 服务器无法正确渲染图像

我正在使用套接字在Java中开发一个简单的HTTP Web服务器.我目前正在开发一项功能，该功能允许我自动呈现静态文件.一切都很好，我可以渲染CSS和JavaScript文件，但由于某种原因，我无法渲染任何图像文件.

打印响应头确实会返回图像字节.当我在调试时查看网络选项卡时，它显示映像路由返回了大约381kB的数据，而映像本身是151kB，所以我假设有什么东西正在返回.

当我转到图像路径时，它显示"图像(目录)无法显示，因为它包含错误."

MochaResponse.java个

package com.gabrielgavrilov.mocha;

import java.io.FileInputStream;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;

public class MochaResponse
{

    public StringBuilder header = new StringBuilder();

    MochaResponse(String status, String contentType)
    {
        this.header.append("HTTP/1.0 " + status + "\r\n");
        this.header.append("Content-Type: " + contentType + "\r\n");
        appendEmpty();
    }

    public void addHeader(String header, String value)
    {
        this.header.append(header + ": " + value + "\r\n");
    }

    public void setCookie(String key, String value)
    {
        addHeader("Set-Cookie", key+"="+value);
    }

    public void send(String data)
    {
        this.header.append(data);
        appendEmpty();
    }

    public void render(String fileName)
    {
        render(fileName, Mocha.VIEWS_DIRECTORY);
    }

    public void render(String fileName, String directory)
    {
        try
        {
            String fileContent = Files.readString(Paths.get(directory + fileName));
            send(fileContent);
        }
        catch (IOException e)
        {
            throw new RuntimeException(e);
        }
    }

    protected void renderImage(String file)
    {
        try
        {
            FileInputStream content = new FileInputStream(Mocha.STATIC_DIRECTORY + file);

            int i = 0;
            while((i = content.read()) != -1)
            {
                this.header.append(i);
            }

            System.out.println(this.header);

            appendEmpty();
            content.close();
        }
        catch(IOException e)
        {
            e.printStackTrace();
        }
    }

    private void appendEmpty()
    {
        this.header.append("\r\n");
    }

}

MochaClient.java个

package com.gabrielgavrilov.mocha;

import java.io.*;
import java.nio.Buffer;
import java.util.HashMap;
import java.util.Map;
import java.util.function.BiConsumer;

public class MochaClient {

    MochaClient(InputStream clientInput, OutputStream clientOutput)
    {
        try
        {
            InputStreamReader sr = new InputStreamReader(clientInput);
            BufferedReader br = new BufferedReader(sr);
            StringBuilder clientHeader = new StringBuilder();

            String line;
            while((line = br.readLine()).length() != 0)
            {
                clientHeader.append(line + "\r\n");
            }

            String route = getRequestedRoute(clientHeader.toString());
            String method = getRequestedMethod(clientHeader.toString());

            handleRequest(clientHeader.toString(), route, method, clientOutput, br);
        }
        catch (IOException e)
        {
            throw new RuntimeException(e);
        }
    }

    private void handleRequest(String header, String route, String method, OutputStream clientOutput, BufferedReader br) throws IOException
    {
        String type = checkForStaticRoute(route);

        if(type != null)
        {
            handleStaticRoute(route, type, clientOutput);
            return;
        }

        switch(method)
        {
            case "GET":
                handleGetRequest(header, route, clientOutput);
                break;
            case "POST":
                handlePostRequest(header, route, clientOutput, br);
                break;
        }
    }

    private String checkForStaticRoute(String route) throws IOException
    {
        if(route.contains("."))
        {
            String[] routeSplit = route.split("\\.");
            return routeSplit[routeSplit.length-1];
        }

        return null;
    }

    private void handleStaticRoute(String route, String type, OutputStream clientOutput) throws IOException
    {
        switch(type)
        {
            case "css":
                renderStaticFile("text/css", route, clientOutput);
                break;
            case "js":
                renderStaticFile("text/javascript", route, clientOutput);
                break;
            case "png":
                renderStaticImage("image/png", route, clientOutput);
                break;
            case "jpeg":
                renderStaticImage("image/jpeg", route, clientOutput);
                break;
        }
    }

    private void renderStaticFile(String contentType, String route, OutputStream clientOutput) throws IOException
    {
        String file = route.substring(1);
        MochaResponse response = new MochaResponse("200 OK", contentType);

        response.render(file, Mocha.STATIC_DIRECTORY);

        clientOutput.write(response.header.toString().getBytes());
        clientOutput.flush();
    }

    private void renderStaticImage(String contentType, String route, OutputStream clientOutput) throws IOException
    {
        String file = route.substring(1);
        MochaResponse response = new MochaResponse("200 OK", contentType);

        response.renderImage(file);

        clientOutput.write(response.header.toString().getBytes());
        clientOutput.flush();
    }

    ...

如果有人能帮我指引正确的方向，我将不胜感激. 谢谢!