JAVA基本類型互相轉換

/**<br /> * <p>TypeChange.java<br /> * <p>JAVA基本類型互相轉換<br /> *<br /> * @author heardy<br /> * @time 2011/01/30<br /> * @version 1.0<br /> */<br />public class TypeChange {</p><p> /**<br /> * 轉為字串<br /> *<br /> * @param obj<br /> * @return 為null時返回Null 字元串<br /> */<br /> public static String objectToString(Object obj) {<br />String str = "";<br />try {<br /> str = (String) obj;<br /> if (str == null) {<br />str = "";<br /> }<br />} catch (ClassCastException ce) {<br /> try {<br />str = String.valueOf(obj);<br /> } catch (Exception e) {<br />str = "";<br /> }<br />}<br />return str.trim();<br /> }</p><p> /**<br /> * 轉null為空白字元<br /> *<br /> * @param str<br /> * @return<br /> */<br /> public static String nullOfString(Object obj) {<br />String str = objectToString(obj);<br />return str;<br /> }</p><p> /**<br /> * 轉null為Int<br /> *<br /> * @param obj<br /> * @return<br /> */<br /> public static int nullOfInt(Object obj) {<br />return objectToInt(obj);<br /> }</p><p> // *****************Object 轉 其他類型*****************</p><p> /**<br /> * 轉位元組<br /> *<br /> * @param str<br /> * @return<br /> * @throws 如果無法轉換<br /> * 拋出 NumberFormatException<br /> */<br /> public static byte objectToByte(Object obj) {<br />String str = objectToString(obj);<br />str = nullOfString(str);<br />try {<br /> return Byte.parseByte(str);<br />} catch (NumberFormatException e) {<br /> System.out.println("轉換出錯" + e);<br /> throw e;<br />}<br /> }</p><p> /**<br /> * 轉布爾<br /> *<br /> * @param str<br /> * @return 為1或"true"返回真 否則假<br /> */<br /> public static boolean objectToBoolean(Object obj) {<br />String str = objectToString(obj);<br />if (str.equals("1")) {<br /> return true;<br />} else if (str.equals("0")) {<br /> return false;<br />} else {<br /> try {<br />return Boolean.parseBoolean(str);<br /> } catch (Exception e) {<br />return false;<br /> }<br />}<br /> }</p><p> /**<br /> * 轉Int<br /> *<br /> * @param str<br /> * @return 相應的值 或 零<br /> */<br /> public static int objectToInt(Object obj) {<br />String str = objectToString(obj);<br />int i = 0;<br />try {<br /> i = Integer.parseInt(str.trim());<br />} catch (NumberFormatException e) {<br /> i = 0;<br />}<br />return i;<br /> }</p><p> /**<br /> * 轉short<br /> *<br /> * @param obj<br /> * @return 相應的值 或 零<br /> */<br /> public static short objectToShort(Object obj) {<br />String str = objectToString(obj);<br />short i = 0;<br />try {<br /> i = Short.parseShort(str.trim());<br />} catch (NumberFormatException e) {<br /> i = 0;<br />}<br />return i;<br /> }</p><p> /**<br /> * 轉Double<br /> *<br /> * @param obj<br /> * @return 相應的值 或 零<br /> */<br /> public static double objectToDouble(Object obj) {<br />String str = objectToString(obj);<br />double i = 0;<br />try {<br /> i = Double.parseDouble(str.trim());<br />} catch (NumberFormatException e) {<br /> i = 0;<br />}<br />return i;<br /> }</p><p> /**<br /> * 轉Long<br /> *<br /> * @param obj<br /> * @return 相應的值 或 零<br /> */<br /> public static long objectToLong(Object obj) {<br />String str = objectToString(obj);<br />Long li = new Long(0);<br />try {<br /> li = Long.valueOf(str);<br />} catch (NumberFormatException e) {<br />}<br />return li.longValue();<br /> }</p><p> // ***************** 其他類型相互轉換 *****************</p><p> /**<br /> * double轉long<br /> *<br /> * @param d<br /> * @return 只截取前面的整數<br /> */<br /> public static long doubleToLong(double d) {<br />long l = 0;<br />try {<br /> // double轉換成long前要過濾掉double類型小數點後資料<br /> l = Long.parseLong(String.valueOf(d).substring(0,<br /> String.valueOf(d).lastIndexOf(".")));<br />} catch (Exception e) {<br /> l = 0;<br />}<br />return l;<br /> }</p><p> /**<br /> * double轉int<br /> *<br /> * @param d<br /> * @return 只截取前面的整數<br /> */<br /> public static int doubleToInt(double d) {<br />int i = 0;<br />try {<br /> // double轉換成Int前要過濾掉double類型小數點後資料<br /> i = Integer.parseInt(String.valueOf(d).substring(0,<br /> String.valueOf(d).lastIndexOf(".")));<br />} catch (Exception e) {<br /> i = 0;<br />}<br />return i;<br /> }</p><p> /**<br /> * double轉long(四捨五入)<br /> *<br /> * @param d<br /> * @return 只截取前面的整數 (四捨五入)<br /> */<br /> public static long doubleToLongWhithRound(double d) {<br />long l = 0;<br />try {<br /> l = Math.round(d);<br />} catch (Exception e) {<br /> l = 0;<br />}<br />return l;<br /> }</p><p> /**<br /> * double轉int(四捨五入)<br /> *<br /> * @param d<br /> * @return 只截取前面的整數 (四捨五入)<br /> */<br /> public static int doubleToIntWhithRound(double d) {<br />int i = 0;<br />try {<br /> i = (int) Math.round(d);<br />} catch (Exception e) {<br /> i = 0;<br />}<br />return i;<br /> }</p><p> public static double longToDouble(long d) {<br />double l = 0;<br />try {<br /> l = Double.parseDouble(String.valueOf(d));<br />} catch (Exception e) {<br /> l = 0;<br />}<br />return l;<br /> }</p><p> public static int longToInt(long d) {<br />int l = 0;<br />try {<br /> l = Integer.parseInt(String.valueOf(d));<br />} catch (Exception e) {<br /> l = 0;<br />}<br />return l;<br /> }<br />}

 

實現了基本類型的轉換...

 

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