本文实例为大家分享了Java常用工具类 的具体代码，供大家参考，具体内容如下
UUID工具类
package com.jarvis.base.util;import java.security.MessageDigest;import java.security.NoSuchAlgorithmException;import java.security.SecureRandom;/** * A class that represents an immutable universally unique identifier (UUID). * A UUID represents a 128-bit value. * <p/> * <p>There exist different variants of these global identifiers. The methods * of this class are for manipulating the Leach-Salz variant, although the * constructors allow the creation of any variant of UUID (described below). * <p/> * <p>The layout of a variant 2 (Leach-Salz) UUID is as follows: * <p/> * The most significant long consists of the following unsigned fields: * <pre> * 0xFFFFFFFF00000000 time_low * 0x00000000FFFF0000 time_mid * 0x000000000000F000 version * 0x0000000000000FFF time_hi * </pre> * The least significant long consists of the following unsigned fields: * <pre> * 0xC000000000000000 variant * 0x3FFF000000000000 clock_seq * 0x0000FFFFFFFFFFFF node * </pre> * <p/> * <p>The variant field contains a value which identifies the layout of * the <tt>UUID</tt>. The bit layout described above is valid only for * a <tt>UUID</tt> with a variant value of 2, which indicates the * Leach-Salz variant. * <p/> * <p>The version field holds a value that describes the type of this * <tt>UUID</tt>. There are four different basic types of UUIDs: time-based, * DCE security, name-based, and randomly generated UUIDs. These types * have a version value of 1, 2, 3 and 4, respectively. * <p/> * <p>For more information including algorithms used to create <tt>UUID</tt>s, * see the Internet-Draft <a href="http://www.ietf.org/internet-drafts/draft-mealling-uuid-urn-03.txt" rel="external nofollow" >UUIDs and GUIDs</a> * or the standards body definition at * <a href="http://www.iso.ch/cate/d2229.html" rel="external nofollow" >ISO/IEC 11578:1996</a>. * * @version 1.14, 07/12/04 * @since 1.5 */@Deprecatedpublic final class UUID implements java.io.Serializable{ /** * Explicit serialVersionUID for interoperability. */ private static final long serialVersionUID = -4856846361193249489L; /* * The most significant 64 bits of this UUID. * * @serial */ private final long mostSigBits; /** * The least significant 64 bits of this UUID. * * @serial */ private final long leastSigBits; /* * The version number associated with this UUID. Computed on demand. */ private transient int version = -1; /* * The variant number associated with this UUID. Computed on demand. */ private transient int variant = -1; /* * The timestamp associated with this UUID. Computed on demand. */ private transient volatile long timestamp = -1; /* * The clock sequence associated with this UUID. Computed on demand. */ private transient int sequence = -1; /* * The node number associated with this UUID. Computed on demand. */ private transient long node = -1; /* * The hashcode of this UUID. Computed on demand. */ private transient int hashCode = -1; /* * The random number generator used by this class to create random * based UUIDs. */ private static volatile SecureRandom numberGenerator = null; // Constructors and Factories /* * Private constructor which uses a byte array to construct the new UUID. */ private UUID(byte[] data) { long msb = 0; long lsb = 0; for (int i = 0; i < 8; i++) msb = (msb << 8) | (data[i] & 0xff); for (int i = 8; i < 16; i++) lsb = (lsb << 8) | (data[i] & 0xff); this.mostSigBits = msb; this.leastSigBits = lsb; } /** * Constructs a new <tt>UUID</tt> using the specified data. * <tt>mostSigBits</tt> is used for the most significant 64 bits * of the <tt>UUID</tt> and <tt>leastSigBits</tt> becomes the * least significant 64 bits of the <tt>UUID</tt>. * * @param mostSigBits * @param leastSigBits */ public UUID(long mostSigBits, long leastSigBits) { this.mostSigBits = mostSigBits; this.leastSigBits = leastSigBits; } /** * Static factory to retrieve a type 4 (pseudo randomly generated) UUID. * <p/> * The <code>UUID</code> is generated using a cryptographically strong * pseudo random number generator. * * @return a randomly generated <tt>UUID</tt>. */ @SuppressWarnings("unused") public static UUID randomUUID() { SecureRandom ng = numberGenerator; if (ng == null) { numberGenerator = ng = new SecureRandom(); } byte[] randomBytes = new byte[16]; ng.nextBytes(randomBytes); randomBytes[6] &= 0x0f; /* clear version */ randomBytes[6] |= 0x40; /* set to version 4 */ randomBytes[8] &= 0x3f; /* clear variant */ randomBytes[8] |= 0x80; /* set to IETF variant */ UUID result = new UUID(randomBytes); return new UUID(randomBytes); } /** * Static factory to retrieve a type 3 (name based) <tt>UUID</tt> based on * the specified byte array. * * @param name a byte array to be used to construct a <tt>UUID</tt>. * @return a <tt>UUID</tt> generated from the specified array. */ public static UUID nameUUIDFromBytes(byte[] name) { MessageDigest md; try { md = MessageDigest.getInstance("MD5"); } catch (NoSuchAlgorithmException nsae) { throw new InternalError("MD5 not supported"); } byte[] md5Bytes = md.digest(name); md5Bytes[6] &= 0x0f; /* clear version */ md5Bytes[6] |= 0x30; /* set to version 3 */ md5Bytes[8] &= 0x3f; /* clear variant */ md5Bytes[8] |= 0x80; /* set to IETF variant */ return new UUID(md5Bytes); } /** * Creates a <tt>UUID</tt> from the string standard representation as * described in the {@link #toString} method. * * @param name a string that specifies a <tt>UUID</tt>. * @return a <tt>UUID</tt> with the specified value. * @throws IllegalArgumentException if name does not conform to the * string representation as described in {@link #toString}. */ public static UUID fromString(String name) { String[] components = name.split("-"); if (components.length != 5) throw new IllegalArgumentException("Invalid UUID string: " + name); for (int i = 0; i < 5; i++) components[i] = "0x" + components[i]; long mostSigBits = Long.decode(components[0]).longValue(); mostSigBits <<= 16; mostSigBits |= Long.decode(components[1]).longValue(); mostSigBits <<= 16; mostSigBits |= Long.decode(components[2]).longValue(); long leastSigBits = Long.decode(components[3]).longValue(); leastSigBits <<= 48; leastSigBits |= Long.decode(components[4]).longValue(); return new UUID(mostSigBits, leastSigBits); } // Field Accessor Methods /** * Returns the least significant 64 bits of this UUID's 128 bit value. * * @return the least significant 64 bits of this UUID's 128 bit value. */ public long getLeastSignificantBits() { return leastSigBits; } /** * Returns the most significant 64 bits of this UUID's 128 bit value. * * @return the most significant 64 bits of this UUID's 128 bit value. */ public long getMostSignificantBits() { return mostSigBits; } /** * The version number associated with this <tt>UUID</tt>. The version * number describes how this <tt>UUID</tt> was generated. * <p/> * The version number has the following meaning:<p> * <ul> * <li>1 Time-based UUID * <li>2 DCE security UUID * <li>3 Name-based UUID * <li>4 Randomly generated UUID * </ul> * * @return the version number of this <tt>UUID</tt>. */ public int version() { if (version < 0) { // Version is bits masked by 0x000000000000F000 in MS long version = (int) ((mostSigBits >> 12) & 0x0f); } return version; } /** * The variant number associated with this <tt>UUID</tt>. The variant * number describes the layout of the <tt>UUID</tt>. * <p/> * The variant number has the following meaning:<p> * <ul> * <li>0 Reserved for NCS backward compatibility * <li>2 The Leach-Salz variant (used by this class) * <li>6 Reserved, Microsoft Corporation backward compatibility * <li>7 Reserved for future definition * </ul> * * @return the variant number of this <tt>UUID</tt>. */ public int variant() { if (variant < 0) { // This field is composed of a varying number of bits if ((leastSigBits >>> 63) == 0) { variant = 0; } else if ((leastSigBits >>> 62) == 2) { variant = 2; } else { variant = (int) (leastSigBits >>> 61); } } return variant; } /** * The timestamp value associated with this UUID. * <p/> * <p>The 60 bit timestamp value is constructed from the time_low, * time_mid, and time_hi fields of this <tt>UUID</tt>. The resulting * timestamp is measured in 100-nanosecond units since midnight, * October 15, 1582 UTC.<p> * <p/> * The timestamp value is only meaningful in a time-based UUID, which * has version type 1. If this <tt>UUID</tt> is not a time-based UUID then * this method throws UnsupportedOperationException. * * @throws UnsupportedOperationException if this UUID is not a * version 1 UUID. */ public long timestamp() { if (version() != 1) { throw new UnsupportedOperationException("Not a time-based UUID"); } long result = timestamp; if (result < 0) { result = (mostSigBits & 0x0000000000000FFFL) << 48; result |= ((mostSigBits >> 16) & 0xFFFFL) << 32; result |= mostSigBits >>> 32; timestamp = result; } return result; } /** * The clock sequence value associated with this UUID. * <p/> * <p>The 14 bit clock sequence value is constructed from the clock * sequence field of this UUID. The clock sequence field is used to * guarantee temporal uniqueness in a time-based UUID.<p> * <p/> * The clockSequence value is only meaningful in a time-based UUID, which * has version type 1. If this UUID is not a time-based UUID then * this method throws UnsupportedOperationException. * * @return the clock sequence of this <tt>UUID</tt>. * @throws UnsupportedOperationException if this UUID is not a * version 1 UUID. */ public int clockSequence() { if (version() != 1) { throw new UnsupportedOperationException("Not a time-based UUID"); } if (sequence < 0) { sequence = (int) ((leastSigBits & 0x3FFF000000000000L) >>> 48); } return sequence; } /** * The node value associated with this UUID. * <p/> * <p>The 48 bit node value is constructed from the node field of * this UUID. This field is intended to hold the IEEE 802 address * of the machine that generated this UUID to guarantee spatial * uniqueness.<p> * <p/> * The node value is only meaningful in a time-based UUID, which * has version type 1. If this UUID is not a time-based UUID then * this method throws UnsupportedOperationException. * * @return the node value of this <tt>UUID</tt>. * @throws UnsupportedOperationException if this UUID is not a * version 1 UUID. */ public long node() { if (version() != 1) { throw new UnsupportedOperationException("Not a time-based UUID"); } if (node < 0) { node = leastSigBits & 0x0000FFFFFFFFFFFFL; } return node; } // Object Inherited Methods /** * Returns a <code>String</code> object representing this * <code>UUID</code>. * <p/> * <p>The UUID string representation is as described by this BNF : * <pre> * UUID = <time_low> "-" <time_mid> "-" * <time_high_and_version> "-" * <variant_and_sequence> "-" * <node> * time_low = 4*<hexOctet> * time_mid = 2*<hexOctet> * time_high_and_version = 2*<hexOctet> * variant_and_sequence = 2*<hexOctet> * node = 6*<hexOctet> * hexOctet = <hexDigit><hexDigit> * hexDigit = * "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" * | "a" | "b" | "c" | "d" | "e" | "f" * | "A" | "B" | "C" | "D" | "E" | "F" * </pre> * * @return a string representation of this <tt>UUID</tt>. */ public String toString() { return (digits(mostSigBits >> 32, 8) + "-" + digits(mostSigBits >> 16, 4) + "-" + digits(mostSigBits, 4) + "-" + digits(leastSigBits >> 48, 4) + "-" + digits(leastSigBits, 12)); } /** * Returns val represented by the specified number of hex digits. */ private static String digits(long val, int digits) { long hi = 1L << (digits * 4); return Long.toHexString(hi | (val & (hi - 1))).substring(1); } /** * Returns a hash code for this <code>UUID</code>. * * @return a hash code value for this <tt>UUID</tt>. */ public int hashCode() { if (hashCode == -1) { hashCode = (int) ((mostSigBits >> 32) ^ mostSigBits ^ (leastSigBits >> 32) ^ leastSigBits); } return hashCode; } /** * Compares this object to the specified object. The result is * <tt>true</tt> if and only if the argument is not * <tt>null</tt>, is a <tt>UUID</tt> object, has the same variant, * and contains the same value, bit for bit, as this <tt>UUID</tt>. * * @param obj the object to compare with. * @return <code>true</code> if the objects are the same; * <code>false</code> otherwise. */ public boolean equals(Object obj) { if (!(obj instanceof UUID)) return false; if (((UUID) obj).variant() != this.variant()) return false; UUID id = (UUID) obj; return (mostSigBits == id.mostSigBits && leastSigBits == id.leastSigBits); } // Comparison Operations /** * Compares this UUID with the specified UUID. * <p/> * <p>The first of two UUIDs follows the second if the most significant * field in which the UUIDs differ is greater for the first UUID. * * @param val <tt>UUID</tt> to which this <tt>UUID</tt> is to be compared. * @return -1, 0 or 1 as this <tt>UUID</tt> is less than, equal * to, or greater than <tt>val</tt>. */ public int compareTo(UUID val) { // The ordering is intentionally set up so that the UUIDs // can simply be numerically compared as two numbers return (this.mostSigBits < val.mostSigBits ? -1 : (this.mostSigBits > val.mostSigBits ? 1 : (this.leastSigBits < val.leastSigBits ? -1 : (this.leastSigBits > val.leastSigBits ? 1 : 0)))); } /** * Reconstitute the <tt>UUID</tt> instance from a stream (that is, * deserialize it). This is necessary to set the transient fields * to their correct uninitialized value so they will be recomputed * on demand. */ private void readObject(java.io.ObjectInputStream in) throws java.io.IOException, ClassNotFoundException { in.defaultReadObject(); // Set "cached computation" fields to their initial values version = -1; variant = -1; timestamp = -1; sequence = -1; node = -1; hashCode = -1; } }
Map工具类
package com.jarvis.base.util;import java.util.Map;/** * * * @Title: MapHelper.java * @Package com.jarvis.base.util * @Description:Map工具类 * @version V1.0 */public class MapHelper { /** * 获得字串值 * * @param name * 键值名称 * @return 若不存在，则返回空字串 */ public static String getString(Map<?, ?> map, String name) { if (name == null || name.equals("")) { return ""; } String value = ""; if (map.containsKey(name) == false) { return ""; } Object obj = map.get(name); if (obj != null) { value = obj.toString(); } obj = null; return value; } /** * 返回整型值 * * @param name * 键值名称 * @return 若不存在，或转换失败，则返回0 */ public static int getInt(Map<?, ?> map, String name) { if (name == null || name.equals("")) { return 0; } int value = 0; if (map.containsKey(name) == false) { return 0; } Object obj = map.get(name); if (obj == null) { return 0; } if (!(obj instanceof Integer)) { try { value = Integer.parseInt(obj.toString()); } catch (Exception ex) { ex.printStackTrace(); System.err.println("name[" + name + "]对应的值不是数字，返回0"); value = 0; } } else { value = ((Integer) obj).intValue(); obj = null; } return value; } /** * 获取长整型值 * * @param name * 键值名称 * @return 若不存在，或转换失败，则返回0 */ public static long getLong(Map<?, ?> map, String name) { if (name == null || name.equals("")) { return 0; } long value = 0; if (map.containsKey(name) == false) { return 0; } Object obj = map.get(name); if (obj == null) { return 0; } if (!(obj instanceof Long)) { try { value = Long.parseLong(obj.toString()); } catch (Exception ex) { ex.printStackTrace(); System.err.println("name[" + name + "]对应的值不是数字，返回0"); value = 0; } } else { value = ((Long) obj).longValue(); obj = null; } return value; } /** * 获取Float型值 * * @param name * 键值名称 * @return 若不存在，或转换失败，则返回0 */ public static float getFloat(Map<?, ?> map, String name) { if (name == null || name.equals("")) { return 0; } float value = 0; if (map.containsKey(name) == false) { return 0; } Object obj = map.get(name); if (obj == null) { return 0; } if (!(obj instanceof Float)) { try { value = Float.parseFloat(obj.toString()); } catch (Exception ex) { ex.printStackTrace(); System.err.println("name[" + name + "]对应的值不是数字，返回0"); value = 0; } } else { value = ((Float) obj).floatValue(); obj = null; } return value; } /** * 获取Double型值 * * @param name * 键值名称 * @return 若不存在，或转换失败，则返回0 */ public static double getDouble(Map<?, ?> map, String name) { if (name == null || name.equals("")) { return 0; } double value = 0; if (map.containsKey(name) == false) { return 0; } Object obj = map.get(name); if (obj == null) { return 0; } if (!(obj instanceof Double)) { try { value = Double.parseDouble(obj.toString()); } catch (Exception ex) { ex.printStackTrace(); System.err.println("name[" + name + "]对应的值不是数字，返回0"); value = 0; } } else { value = ((Double) obj).doubleValue(); obj = null; } return value; } /** * 获取Bool值 * * @param name * 键值名称 * @return 若不存在，或转换失败，则返回false */ public static boolean getBoolean(Map<?, ?> map, String name) { if (name == null || name.equals("")) { return false; } boolean value = false; if (map.containsKey(name) == false) { return false; } Object obj = map.get(name); if (obj == null) { return false; } if (obj instanceof Boolean) { return ((Boolean) obj).booleanValue(); } value = Boolean.valueOf(obj.toString()).booleanValue(); obj = null; return value; }}
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本文标题: java常用工具类 UUID、Map工具类
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