初学java的时候，我们不会写代码，其实这时候不妨趁有空的时候多背一些java代码，这样在进行java项目的时候，说不定还能用得了呢!那java初学者必背代码有哪些?下面来我们就来给大家讲解一下。
1. 字符串有整型的相互转换
String a = String.valueOf(2); //integer to numeric string int i = Integer.parseInt(a); //numeric string to an int
2. 向文件末尾添加内容
BufferedWriter out = null;
try
{
out = new BufferedWriter(new FileWriter(”filename”, true));
out.write(”aString”);
}
catch (IOException e)
{ // error processing code } finally { if (out != null) { out.close(); } }3. 得到当前方法的名字
String methodName = Thread.currentThread() .getStackTrace()[1].getMethodName();
4. 转字符串到日期
java.util.Date = java.text.DateFormat.getDateInstance()
.parse(date String);
或者是： SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
Date date = format.parse(myString);5、类的属性和方法
public class Liwl
{
public String name = "liwanliang";
public Integer age = 30;
public static void main(String[] args)
{
Liwl liwl01 = new Liwl();
//liwl01.name = "hello,world"
System.out.println(liwl01.age)
}
} //通过liwl01.name = "hello,world"的语句，无法保证类的安全性，不太满足类的封装6、列出文件和目录
File dir = new File("directoryName");
String children = dir.list;
if (children == )
{
// Either dir does not exist or is not a directory
}
else
{
for (int i = 0; i < children.length; i++)
{
// Get filename of file or directory
String filename = children[i];
}
}
// It is also possible to filter the list of returned files.
// This example does not return any files that start with `.'.
FilenameFilter filter = new FilenameFilter
{
public boolean accept(File dir, String name)
{
return !name.startsWith(".");
}
};
children = dir.list(filter);
// The list of files can also be retrieved as File objects
File files = dir.listFiles;
// This filter only returns directories
FileFilter fileFilter = new FileFilter
{
public boolean accept(File file)
{
return file.isDirectory;
}
};
files = dir.listFiles(fileFilter);多背java代码其实是积累java知识的一种方式，很多java开发语句我们不会写的时候，就可以将代码背下来，然后灵活应用!最后大家如果想要了解更多初识java知识，敬请关注奇Q工具网。
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