Springboot使用filter对response内容进行加密方式

下面是“Springboot使用filter对response内容进行加密方式”的完整攻略：

一、添加依赖

在pom.xml文件中添加以下依赖：

<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-security</artifactId>
</dependency>
<dependency>
  <groupId>org.springframework.security</groupId>
  <artifactId>spring-security-crypto</artifactId>
</dependency>

二、编写Filter

新建一个类（例如：EncryptFilter），继承OncePerRequestFilter，并重写doFilterInternal方法，实现对response内容的加密：

import org.springframework.security.crypto.codec.Hex;
import org.springframework.security.crypto.encrypt.BytesEncryptor;
import org.springframework.security.crypto.encrypt.Encryptors;
import org.springframework.security.crypto.encrypt.TextEncryptor;
import org.springframework.security.web.util.matcher.RequestMatcher;
import org.springframework.util.Base64Utils;
import org.springframework.web.filter.OncePerRequestFilter;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Arrays;

public class EncryptFilter extends OncePerRequestFilter {

    private TextEncryptor encryptor;
    private RequestMatcher requestMatcher;

    public EncryptFilter(byte[] salt, String password, RequestMatcher requestMatcher) {
        BytesEncryptor bytesEncryptor = Encryptors.standard(password, new String(Hex.encode(salt)));
        encryptor = new BinaryEncryptor(bytesEncryptor);
        this.requestMatcher = requestMatcher;
    }

    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {

        if (requestMatcher.matches(request)) {
            EncryptResponseWrapper wrappedResponse = new EncryptResponseWrapper(response, encryptor);
            filterChain.doFilter(request, wrappedResponse);

            byte[] encryptedBytes = wrappedResponse.getEncryptBytes();
            response.setHeader("Content-Type", "application/octet-stream");
            response.setHeader("Content-Encoding", "encrypt");
            response.getOutputStream().write(Base64Utils.encode(encryptedBytes));
        } else {
            filterChain.doFilter(request, response);
        }
    }

    private static class EncryptResponseWrapper extends ServletOutputStream {

        private final ServletOutputStream delegate;
        private final TextEncryptor encryptor;
        private final byte[] buffer = new byte[8192];
        private int count = 0;

        EncryptResponseWrapper(HttpServletResponse response, TextEncryptor encryptor) throws IOException {
            delegate = response.getOutputStream();
            this.encryptor = encryptor;
        }

        @Override
        public void write(int b) throws IOException {
            if (count == buffer.length) {
                flush();
            }
            buffer[count++] = (byte) b;
        }

        public byte[] getEncryptBytes() {
             flush();
             return encryptor.encrypt(Arrays.copyOf(buffer, count)).getBytes();
        }

        @Override
        public void flush() throws IOException {
             if (count > 0) {
                 byte[] encryptedBytes = encryptor.encrypt(Arrays.copyOf(buffer, count)).getBytes();
                 delegate.write(encryptedBytes);
                 count = 0;
             }
        }
    }
}

三、配置Filter

在Springboot启动类中添加Filter：

@Configuration
public class AppConfig {

    @Bean
    public Filter encryptFilter() {
        byte[] salt = new byte[] {0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8};
        String password = "password";
        RequestMatcher urlMatcher = new AntPathRequestMatcher("/api/**");  // 过滤/api/开头的URL
        return new EncryptFilter(salt, password, urlMatcher);
    }
}

四、进行测试

启动Springboot后，访问http://localhost:8080/api/test，可以看到Response内容被加密了。

另外一个示例：

假设要加密的内容不是字符串，而是一个POJO（如Person），可以修改EncryptFilter中的doFilterInternal方法：

if (requestMatcher.matches(request)) {
    EncryptResponseWrapper wrappedResponse = new EncryptResponseWrapper(response, encryptor);
    filterChain.doFilter(request, wrappedResponse);

    Gson gson = new Gson();
    byte[] encryptedBytes = encryptor.encrypt(gson.toJson(wrappedResponse.getEntity()).getBytes("UTF-8")).getBytes("UTF-8");
    response.setHeader("Content-Type", "application/octet-stream");
    response.setHeader("Content-Encoding", "encrypt");
    response.getOutputStream().write(Base64Utils.encode(encryptedBytes));
} else {
    filterChain.doFilter(request, response);
}

这样，我们就可以加密Person对象了。

以上就是“Springboot使用filter对response内容进行加密方式”的完整攻略。希望能对你有所帮助！