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;
@Deprecated
public final class UUID implements java.io.Serializable
{
private static final long serialVersionUID = -4856846361193249489L;
private final long mostSigBits;
private final long leastSigBits;
private transient int version = -1;
private transient int variant = -1;
private transient volatile long timestamp = -1;
private transient int sequence = -1;
private transient long node = -1;
private transient int hashCode = -1;
private static volatile SecureRandom numberGenerator = null;
// Constructors and Factories
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;
}
public UUID(long mostSigBits, long leastSigBits)
{
this.mostSigBits = mostSigBits;
this.leastSigBits = leastSigBits;
}
@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;
randomBytes[6] |= 0x40;
randomBytes[8] &= 0x3f;
randomBytes[8] |= 0x80;
UUID result = new UUID(randomBytes);
return new UUID(randomBytes);
}
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;
md5Bytes[6] |= 0x30;
md5Bytes[8] &= 0x3f;
md5Bytes[8] |= 0x80;
return new UUID(md5Bytes);
}
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
public long getLeastSignificantBits()
{
return leastSigBits;
}
public long getMostSignificantBits()
{
return mostSigBits;
}
public int version()
{
if (version < 0)
{
// Version is bits masked by 0x000000000000F000 in MS long
version = (int) ((mostSigBits >> 12) & 0x0f);
}
return version;
}
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;
}
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;
}
public int clockSequence()
{
if (version() != 1)
{
throw new UnsupportedOperationException("Not a time-based UUID");
}
if (sequence < 0)
{
sequence = (int) ((leastSigBits & 0x3FFF000000000000L) >>> 48);
}
return sequence;
}
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
public String toString()
{
return (digits(mostSigBits >> 32, 8) + "-" +
digits(mostSigBits >> 16, 4) + "-" +
digits(mostSigBits, 4) + "-" +
digits(leastSigBits >> 48, 4) + "-" +
digits(leastSigBits, 12));
}
private static String digits(long val, int digits)
{
long hi = 1L << (digits * 4);
return Long.toHexString(hi | (val & (hi - 1))).substring(1);
}
public int hashCode()
{
if (hashCode == -1)
{
hashCode = (int) ((mostSigBits >> 32) ^
mostSigBits ^
(leastSigBits >> 32) ^
leastSigBits);
}
return hashCode;
}
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
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))));
}
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;
public class MapHelper {
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;
}
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;
}
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;
}
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;
}
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;
}
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;
}
}
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持考高分网。
