Accessing Files with the java.nio.file package

java.nio.file preferred packages for files

• java.nio.FileXXX streams are deprecated

Provide a number of benefits over java.io

• Better exception reporting
• Greater scalabity - large file system
• More file system feature support
• Simplifies common task

常用class

Path

• Used to locate a file system item
• Can be a file or directory

Paths

• Static Path factory methods
• From string-based hierarchical path
• From URI

Path p1 = Paths.get("\\documents\\data\\foo.txt");
Path p2 = Paths.get("\\documents","data","foo.txt");
           

Files

• Static methods for interacting with files
• Create, copy, delete, etc.
• Open file streams
  • new BufferedReader
  • new BufferedWriter
  • new InputStream
  • new OutputStream
• Convenience methods - read/write file contents
  • readAllLines

// Template - Reading Lines with BufferedReader
void readData() throws IOException{
try (BufferedReader br = Files.newBufferedReader(Paths.get("data.txt"))){
	String inValue;
	while((inValue = br.readLine()) != null){
		System.out.println(inValue);
	}
  }
}

// Read All Lines
void readThemAll() throws IOException{
	List<String> lines = Files.readAllLines(Paths.get("data.txt"));
	
	for(String line: lines)
		System.out.println(line);
}