1.) String s = String.valueOf(i);2.) String s = Integer.toString(i);

1). int i = Integer.parseInt([String]); 或

i = Integer.parseInt([String],[int radix]);

2). int i = Integer.valueOf(my_str).intValue();

String[] arr = new String[] {"str1", "str2"};  List<String> list = Arrays.asList(arr);

final int size =　list.size();String[] arr = (String[])list.toArray(new String[size]);

String[] value = line.split(" ");

1、分隔符为“.”(无输出),“|”(不能得到正确结果)转义字符时,“*”,“+”时出错抛出异常,都必须在前面加必须得加"\\",如split(\\|);2、如果用"\"作为分隔,就得写成这样：String.split("\\\\"),因为在Java中是用"\\"来表示"\"的,字符串得写成这样：String Str="a\\b\\c";?转义字符,必须得加"\\";3、如果在一个字符串中有多个分隔符,可以用"|"作为连字符,比如：String str="Java string-split#test",可以用Str.split(" |-|#")把每个字符串分开;

public static void main(String[] srgs){String strline2= "123-12-12342323";String regex2 ="[0-9]{3}\\-[0-9]{2}\\-[0-9]{4}";String strline1= "11:08:56.149361 IP ";String regex1 ="([0-2][0-4]):([0-5][0-9]):([0-5][0-9]).[0-9]{6}";String strline3= "0x0000:  4500 003c c437 4000 4006 63cb c0a8 0078  E..<.7@.@.c....x";String regex3 ="0x[0-9]{4}:  ([A-Za-z0-9]{4} )+"; Pattern pattern1=Pattern.compile(regex3);        Matcher match1=pattern1.matcher(strline3);        while(match1.find()){        System.out.println(match1.group());        String hexline = match1.group();String regexHex2 ="([A-Za-z0-9]{4} )+";Pattern patternHex2 = Pattern.compile(regexHex2);Matcher matchHex2 = patternHex2.matcher(hexline);while (matchHex2.find()) {System.out.println(matchHex2.group());}        }}

// 写文件 append方式public static boolean writeFile(String file, String fileContent) {try {BufferedWriter buffwrite = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file, true),"utf-8"));buffwrite.write(fileContent);buffwrite.flush();buffwrite.close();} catch (UnsupportedEncodingException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (FileNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}return true;}