feat(demo-util): add some useful tool class

Author: helltractor

demo-util/pom.xml

@@ -12,4 +12,21 @@
 
     <artifactId>demo-util</artifactId>
 
+    <dependencies>
+        <dependency>
+            <groupId>jakarta.servlet</groupId>
+            <artifactId>jakarta.servlet-api</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-api</artifactId>
+        </dependency>
+    </dependencies>
+
 </project>

demo-util/src/main/java/com/helltractor/demo/util/ByteUtil.java

@@ -0,0 +1,27 @@
+package com.helltractor.demo.util;
+
+
+import java.util.HexFormat;
+
+public class ByteUtil {
+    
+    /**
+     * Convert bytes to hex string (all lower-case).
+     *
+     * @param b Input bytes.
+     * @return Hex string.
+     */
+    public static String toHexString(byte[] b) {
+        return HexFormat.of().formatHex(b);
+    }
+    
+    /**
+     * Convert byte to hex string (all lower-case).
+     *
+     * @param b Input bytes.
+     * @return Hex string.
+     */
+    public static String toHex(byte b) {
+        return toHexString(new byte[]{b});
+    }
+}

demo-util/src/main/java/com/helltractor/demo/util/HashUtil.java

@@ -0,0 +1,79 @@
+package com.helltractor.demo.util;
+
+import javax.crypto.Mac;
+import javax.crypto.SecretKey;
+import javax.crypto.spec.SecretKeySpec;
+import java.nio.charset.StandardCharsets;
+import java.security.GeneralSecurityException;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+
+/**
+ * Utility class for hashing.
+ */
+public class HashUtil {
+    
+    /**
+     * Generate SHA-256 as hex string (all lower-case).
+     *
+     * @param input Input as String.
+     * @return Hex string.
+     */
+    public static String sha256(String input) {
+        return sha256(input.getBytes(StandardCharsets.UTF_8));
+    }
+    
+    /**
+     * Generate SHA-256 as hex string (all lower-case).
+     *
+     * @param input Input as bytes.
+     * @return Hex string.
+     */
+    public static String sha256(byte[] input) {
+        MessageDigest md = null;
+        try {
+            md = MessageDigest.getInstance("SHA-256");
+        } catch (NoSuchAlgorithmException e) {
+            throw new RuntimeException(e);
+        }
+        md.update(input);
+        byte[] digest = md.digest();
+        return ByteUtil.toHexString(digest);
+    }
+    
+    /**
+     * Do HMAC-SHA256.
+     *
+     * @return Hex string.
+     */
+    public static byte[] hmacSha256AsBytes(byte[] data, byte[] key) {
+        SecretKey skey = new SecretKeySpec(key, "HmacSHA256");
+        Mac mac;
+        try {
+            mac = Mac.getInstance("HmacSHA256");
+            mac.init(skey);
+        } catch (GeneralSecurityException e) {
+            throw new RuntimeException(e);
+        }
+        mac.update(data);
+        return mac.doFinal();
+    }
+    
+    /**
+     * Do HMAC-SHA256.
+     *
+     * @return Hex string.
+     */
+    public static String hmacSha256(byte[] data, byte[] key) {
+        return ByteUtil.toHexString(hmacSha256AsBytes(data, key));
+    }
+    
+    /**
+     * Do HMAC-SHA256.
+     *
+     * @return byte[] as result.
+     */
+    public static String hmacSha256(String data, String key) {
+        return hmacSha256(data.getBytes(StandardCharsets.UTF_8), key.getBytes(StandardCharsets.UTF_8));
+    }
+}

demo-util/src/main/java/com/helltractor/demo/util/HttpUtil.java

@@ -0,0 +1,14 @@
+package com.helltractor.demo.util;
+
+import jakarta.servlet.http.HttpServletRequest;
+
+public class HttpUtil {
+    
+    public static boolean isSecure(HttpServletRequest request) {
+        String forwarded = request.getHeader("x-forwarded-proto");
+        if (forwarded != null) {
+            return "https".equals(forwarded);
+        }
+        return "https".equals(request.getScheme());
+    }
+}

demo-util/src/main/java/com/helltractor/demo/util/IdUtil.java

@@ -0,0 +1,22 @@
+package com.helltractor.demo.util;
+
+import java.util.UUID;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public class IdUtil {
+    
+    static Pattern STRING_ID_PATTERN = Pattern.compile("^[a-zA-Z0-9]{1,32}$");
+    
+    public static String generateUniqueId() {
+        return UUID.randomUUID().toString().replace("-", "");
+    }
+    
+    public static boolean isValidStringId(String id) {
+        if (id == null || id.isEmpty()) {
+            return false;
+        }
+        Matcher matcher = STRING_ID_PATTERN.matcher(id);
+        return matcher.matches();
+    }
+}

demo-util/src/main/java/com/helltractor/demo/util/IpUtil.java

@@ -0,0 +1,76 @@
+package com.helltractor.demo.util;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.net.Inet4Address;
+import java.net.InetAddress;
+import java.net.NetworkInterface;
+import java.util.ArrayList;
+import java.util.Enumeration;
+import java.util.List;
+
+/**
+ * IpUtil to get IP address.
+ */
+public class IpUtil {
+    
+    static final Logger logger = LoggerFactory.getLogger(IpUtil.class);
+    
+    static final String IP;
+    
+    static final String HOST_ID;
+    
+    static {
+        IP = doGetIpAddress();
+        HOST_ID = doGetHostId();
+        logger.info("get ip address: {}, host id: {}", IP, HOST_ID);
+    }
+    
+    /**
+     * Get localhost's IP address as string.
+     *
+     * @return IP address like "10.0.1.127"
+     */
+    public static String getIpAddress() {
+        return IP;
+    }
+    
+    public static String getHostId() {
+        return HOST_ID;
+    }
+    
+    static String doGetHostId() {
+        String id = getIpAddress();
+        return id.replace(".", "_").replace("-", "_");
+    }
+    
+    static String doGetIpAddress() {
+        List<InetAddress> ipList = new ArrayList<>();
+        try {
+            Enumeration<NetworkInterface> iterInterface = NetworkInterface.getNetworkInterfaces();
+            while (iterInterface.hasMoreElements()) {
+                NetworkInterface network = iterInterface.nextElement();
+                if (network.isLoopback() || !network.isUp()) {
+                    continue;
+                }
+                Enumeration<InetAddress> itAddr = network.getInetAddresses();
+                while (itAddr.hasMoreElements()) {
+                    InetAddress addr = itAddr.nextElement();
+                    if (!addr.isLoopbackAddress() && (addr instanceof Inet4Address)) {
+                        ipList.add(addr);
+                    }
+                }
+            }
+        } catch (Exception e) {
+            logger.warn("Get IP address by NetworkInterface.getNetworkInterfaces() failed: {}", e.getMessage());
+        }
+        ipList.forEach((ip) -> {
+            logger.debug("Found ip address: {}", ip.getHostAddress());
+        });
+        if (ipList.isEmpty()) {
+            return "127.0.0.1";
+        }
+        return ipList.get(0).getHostAddress();
+    }
+}