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【编程开发】之 Java 开发常用工具 Utils 类

乐寒
2023-12-01

目录


JWT 工具类 JwtUtils

依赖:

<!-- JWT-->
<dependency>
    <groupId>io.jsonwebtoken</groupId>
    <artifactId>jjwt</artifactId>
    <version>0.7.0</version>
</dependency>

工具类文件:JwtUtils.java

import io.jsonwebtoken.Claims;
import io.jsonwebtoken.Jws;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;
import org.springframework.util.StringUtils;

import javax.servlet.http.HttpServletRequest;
import java.util.Date;

/**
 * @author 王廷云
 * @since 2020/08/16
 */
public class JwtUtils {

    //常量
    public static final long EXPIRE = 1000 * 60 * 60 * 24; //token过期时间
    public static final String APP_SECRET = "ukc8BDbRigUDaY6pZFfWus2jZWLPHO"; //秘钥

    //生成token字符串的方法
    public static String getJwtToken(String id, String nickname){

        String JwtToken = Jwts.builder()
                .setHeaderParam("typ", "JWT")
                .setHeaderParam("alg", "HS256")

                .setSubject("edushop-user")
                .setIssuedAt(new Date())
                .setExpiration(new Date(System.currentTimeMillis() + EXPIRE))

                .claim("id", id)  //设置token主体部分 ,存储用户信息
                .claim("nickname", nickname)

                .signWith(SignatureAlgorithm.HS256, APP_SECRET)
                .compact();

        return JwtToken;
    }

    /**
     * 判断token是否存在与有效
     * @param jwtToken
     * @return
     */
    public static boolean checkToken(String jwtToken) {
        if(StringUtils.isEmpty(jwtToken)) return false;
        try {
            Jwts.parser().setSigningKey(APP_SECRET).parseClaimsJws(jwtToken);
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
        return true;
    }

    /**
     * 判断token是否存在与有效
     * @param request
     * @return
     */
    public static boolean checkToken(HttpServletRequest request) {
        try {
            String jwtToken = request.getHeader("token");
            if(StringUtils.isEmpty(jwtToken)) return false;
            Jwts.parser().setSigningKey(APP_SECRET).parseClaimsJws(jwtToken);
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
        return true;
    }

    /**
     * 根据token字符串获取会员id
     * @param request
     * @return
     */
    public static String getMemberIdByJwtToken(HttpServletRequest request) {
        String jwtToken = request.getHeader("token");
        if(StringUtils.isEmpty(jwtToken)) return "";
        Jws<Claims> claimsJws = Jwts.parser().setSigningKey(APP_SECRET).parseClaimsJws(jwtToken);
        Claims claims = claimsJws.getBody();
        return (String)claims.get("id");
    }
}

MD5 工具类 MD5Utils.java

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class MD5Utils {

    public static String encrypt(String strSrc) {
        try {
            char hexChars[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8',
                    '9', 'a', 'b', 'c', 'd', 'e', 'f' };
            byte[] bytes = strSrc.getBytes();
            MessageDigest md = MessageDigest.getInstance("MD5");
            md.update(bytes);
            bytes = md.digest();
            int j = bytes.length;
            char[] chars = new char[j * 2];
            int k = 0;
            for (int i = 0; i < bytes.length; i++) {
                byte b = bytes[i];
                chars[k++] = hexChars[b >>> 4 & 0xf];
                chars[k++] = hexChars[b & 0xf];
            }
            return new String(chars);
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
            throw new RuntimeException("MD5加密出错!!+" + e);
        }
    }

    public static void main(String[] args) {
        System.out.println(encrypt("123456"));
    }
}

HTTP 请求工具类 HttpClientUtils

依赖:

<!--httpclient-->
<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5.1</version>
</dependency>
<!--commons-io-->
<dependency>
    <groupId>commons-io</groupId>
    <artifactId>commons-io</artifactId>
    <version>2.6</version>
</dependency>

工具类文件:HttpClientUtils.java

import org.apache.commons.io.IOUtils;
import org.apache.commons.lang3.StringUtils;
import org.apache.http.Consts;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.config.RequestConfig.Builder;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.conn.ConnectTimeoutException;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.conn.ssl.SSLContextBuilder;
import org.apache.http.conn.ssl.TrustStrategy;
import org.apache.http.conn.ssl.X509HostnameVerifier;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.message.BasicNameValuePair;

import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLException;
import javax.net.ssl.SSLSession;
import javax.net.ssl.SSLSocket;
import java.io.IOException;
import java.net.SocketTimeoutException;
import java.security.GeneralSecurityException;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

/**
 *  依赖的jar包有:commons-lang-2.6.jar、httpclient-4.3.2.jar、httpcore-4.3.1.jar、commons-io-2.4.jar
 */
public class HttpClientUtils {

    public static final int connTimeout=10000;
    public static final int readTimeout=10000;
    public static final String charset="UTF-8";
    private static HttpClient client = null;

    static {
        PoolingHttpClientConnectionManager cm = new PoolingHttpClientConnectionManager();
        cm.setMaxTotal(128);
        cm.setDefaultMaxPerRoute(128);
        client = HttpClients.custom().setConnectionManager(cm).build();
    }

    public static String postParameters(String url, String parameterStr) throws ConnectTimeoutException, SocketTimeoutException, Exception{
        return post(url,parameterStr,"application/x-www-form-urlencoded",charset,connTimeout,readTimeout);
    }

    public static String postParameters(String url, String parameterStr,String charset, Integer connTimeout, Integer readTimeout) throws ConnectTimeoutException, SocketTimeoutException, Exception{
        return post(url,parameterStr,"application/x-www-form-urlencoded",charset,connTimeout,readTimeout);
    }

    public static String postParameters(String url, Map<String, String> params) throws ConnectTimeoutException,
            SocketTimeoutException, Exception {
        return postForm(url, params, null, connTimeout, readTimeout);
    }

    public static String postParameters(String url, Map<String, String> params, Integer connTimeout,Integer readTimeout) throws ConnectTimeoutException,
            SocketTimeoutException, Exception {
        return postForm(url, params, null, connTimeout, readTimeout);
    }

    public static String get(String url) throws Exception {
        return get(url, charset, null, null);
    }

    public static String get(String url, String charset) throws Exception {
        return get(url, charset, connTimeout, readTimeout);
    }

    /**
     * 发送一个 Post 请求, 使用指定的字符集编码.
     *
     * @param url
     * @param body RequestBody
     * @param mimeType 例如 application/xml "application/x-www-form-urlencoded" a=1&b=2&c=3
     * @param charset 编码
     * @param connTimeout 建立链接超时时间,毫秒.
     * @param readTimeout 响应超时时间,毫秒.
     * @return ResponseBody, 使用指定的字符集编码.
     * @throws ConnectTimeoutException 建立链接超时异常
     * @throws SocketTimeoutException  响应超时
     * @throws Exception
     */
    public static String post(String url, String body, String mimeType,String charset, Integer connTimeout, Integer readTimeout)
            throws ConnectTimeoutException, SocketTimeoutException, Exception {
        HttpClient client = null;
        HttpPost post = new HttpPost(url);
        String result = "";
        try {
            if (StringUtils.isNotBlank(body)) {
                HttpEntity entity = new StringEntity(body, ContentType.create(mimeType, charset));
                post.setEntity(entity);
            }
            // 设置参数
            Builder customReqConf = RequestConfig.custom();
            if (connTimeout != null) {
                customReqConf.setConnectTimeout(connTimeout);
            }
            if (readTimeout != null) {
                customReqConf.setSocketTimeout(readTimeout);
            }
            post.setConfig(customReqConf.build());

            HttpResponse res;
            if (url.startsWith("https")) {
                // 执行 Https 请求.
                client = createSSLInsecureClient();
                res = client.execute(post);
            } else {
                // 执行 Http 请求.
                client = HttpClientUtils.client;
                res = client.execute(post);
            }
            result = IOUtils.toString(res.getEntity().getContent(), charset);
        } finally {
            post.releaseConnection();
            if (url.startsWith("https") && client != null&& client instanceof CloseableHttpClient) {
                ((CloseableHttpClient) client).close();
            }
        }
        return result;
    }


    /**
     * 提交form表单
     *
     * @param url
     * @param params
     * @param connTimeout
     * @param readTimeout
     * @return
     * @throws ConnectTimeoutException
     * @throws SocketTimeoutException
     * @throws Exception
     */
    public static String postForm(String url, Map<String, String> params, Map<String, String> headers, Integer connTimeout,Integer readTimeout) throws ConnectTimeoutException,
            SocketTimeoutException, Exception {

        HttpClient client = null;
        HttpPost post = new HttpPost(url);
        try {
            if (params != null && !params.isEmpty()) {
                List<NameValuePair> formParams = new ArrayList<NameValuePair>();
                Set<Entry<String, String>> entrySet = params.entrySet();
                for (Entry<String, String> entry : entrySet) {
                    formParams.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
                }
                UrlEncodedFormEntity entity = new UrlEncodedFormEntity(formParams, Consts.UTF_8);
                post.setEntity(entity);
            }

            if (headers != null && !headers.isEmpty()) {
                for (Entry<String, String> entry : headers.entrySet()) {
                    post.addHeader(entry.getKey(), entry.getValue());
                }
            }
            // 设置参数
            Builder customReqConf = RequestConfig.custom();
            if (connTimeout != null) {
                customReqConf.setConnectTimeout(connTimeout);
            }
            if (readTimeout != null) {
                customReqConf.setSocketTimeout(readTimeout);
            }
            post.setConfig(customReqConf.build());
            HttpResponse res = null;
            if (url.startsWith("https")) {
                // 执行 Https 请求.
                client = createSSLInsecureClient();
                res = client.execute(post);
            } else {
                // 执行 Http 请求.
                client = HttpClientUtils.client;
                res = client.execute(post);
            }
            return IOUtils.toString(res.getEntity().getContent(), "UTF-8");
        } finally {
            post.releaseConnection();
            if (url.startsWith("https") && client != null
                    && client instanceof CloseableHttpClient) {
                ((CloseableHttpClient) client).close();
            }
        }
    }




    /**
     * 发送一个 GET 请求
     *
     * @param url
     * @param charset
     * @param connTimeout  建立链接超时时间,毫秒.
     * @param readTimeout  响应超时时间,毫秒.
     * @return
     * @throws ConnectTimeoutException   建立链接超时
     * @throws SocketTimeoutException   响应超时
     * @throws Exception
     */
    public static String get(String url, String charset, Integer connTimeout,Integer readTimeout)
            throws ConnectTimeoutException,SocketTimeoutException, Exception {

        HttpClient client = null;
        HttpGet get = new HttpGet(url);
        String result = "";
        try {
            // 设置参数
            Builder customReqConf = RequestConfig.custom();
            if (connTimeout != null) {
                customReqConf.setConnectTimeout(connTimeout);
            }
            if (readTimeout != null) {
                customReqConf.setSocketTimeout(readTimeout);
            }
            get.setConfig(customReqConf.build());

            HttpResponse res = null;

            if (url.startsWith("https")) {
                // 执行 Https 请求.
                client = createSSLInsecureClient();
                res = client.execute(get);
            } else {
                // 执行 Http 请求.
                client = HttpClientUtils.client;
                res = client.execute(get);
            }

            result = IOUtils.toString(res.getEntity().getContent(), charset);
        } finally {
            get.releaseConnection();
            if (url.startsWith("https") && client != null && client instanceof CloseableHttpClient) {
                ((CloseableHttpClient) client).close();
            }
        }
        return result;
    }


    /**
     * 从 response 里获取 charset
     *
     * @param ressponse
     * @return
     */
    @SuppressWarnings("unused")
    private static String getCharsetFromResponse(HttpResponse ressponse) {
        // Content-Type:text/html; charset=GBK
        if (ressponse.getEntity() != null  && ressponse.getEntity().getContentType() != null && ressponse.getEntity().getContentType().getValue() != null) {
            String contentType = ressponse.getEntity().getContentType().getValue();
            if (contentType.contains("charset=")) {
                return contentType.substring(contentType.indexOf("charset=") + 8);
            }
        }
        return null;
    }



    /**
     * 创建 SSL连接
     * @return
     * @throws GeneralSecurityException
     */
    private static CloseableHttpClient createSSLInsecureClient() throws GeneralSecurityException {
        try {
            SSLContext sslContext = new SSLContextBuilder().loadTrustMaterial(null, new TrustStrategy() {
                public boolean isTrusted(X509Certificate[] chain,String authType) throws CertificateException {
                    return true;
                }
            }).build();

            SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(sslContext, new X509HostnameVerifier() {

                @Override
                public boolean verify(String arg0, SSLSession arg1) {
                    return true;
                }

                @Override
                public void verify(String host, SSLSocket ssl)
                        throws IOException {
                }

                @Override
                public void verify(String host, X509Certificate cert)
                        throws SSLException {
                }

                @Override
                public void verify(String host, String[] cns,
                                   String[] subjectAlts) throws SSLException {
                }

            });

            return HttpClients.custom().setSSLSocketFactory(sslsf).build();

        } catch (GeneralSecurityException e) {
            throw e;
        }
    }

    public static void main(String[] args) {
        try {
            String str= post("https://localhost:443/ssl/test.shtml","name=12&page=34","application/x-www-form-urlencoded", "UTF-8", 10000, 10000);
            //String str= get("https://localhost:443/ssl/test.shtml?name=12&page=34","GBK");
            /*Map<String,String> map = new HashMap<String,String>();
            map.put("name", "111");
            map.put("page", "222");
            String str= postForm("https://localhost:443/ssl/test.shtml",map,null, 10000, 10000);*/
            System.out.println(str);
        } catch (ConnectTimeoutException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (SocketTimeoutException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

}

随机数工具类 RandomUtils

import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Random;

/**
 * 获取随机数
 *
 * @author 王廷云
 *
 */
public class RandomUtils {

    private static final Random random = new Random();

    private static final DecimalFormat fourdf = new DecimalFormat("0000");

    private static final DecimalFormat sixdf = new DecimalFormat("000000");

    public static String getFourBitRandom() {
        return fourdf.format(random.nextInt(10000));
    }

    public static String getSixBitRandom() {
        return sixdf.format(random.nextInt(1000000));
    }

    /**
     * 给定数组,抽取n个数据
     * @param list
     * @param n
     * @return
     */
    public static ArrayList getRandom(List list, int n) {

        Random random = new Random();

        HashMap<Object, Object> hashMap = new HashMap<Object, Object>();

        // 生成随机数字并存入HashMap
        for (int i = 0; i < list.size(); i++) {

            int number = random.nextInt(100) + 1;

            hashMap.put(number, i);
        }

        // 从HashMap导入数组
        Object[] robjs = hashMap.values().toArray();

        ArrayList r = new ArrayList();

        // 遍历数组并打印数据
        for (int i = 0; i < n; i++) {
            r.add(list.get((int) robjs[i]));
            System.out.print(list.get((int) robjs[i]) + "\t");
        }
        System.out.print("\n");
        return r;
    }
}
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