仅在树莓派上出现java.lang.NoSuchMethodError

Question

I'm running Eclipse Kepler Service Release 2. My program works fine when I run it in Eclipse, and it also works fine when I run the .jar using windows cmd. However, putting that same .jar onto a raspberry pi, I get the following error:

Exception in thread "Thread-1" java.lang.NoSuchMethodError: java.nio.file.Files.readAllLines(Ljava/nio/file/Path;)Ljava/util/List;

The bits of code in question are

import java.nio.file.Files;
import java.nio.file.Path;

import dataTypes.Detection;

public final class FileOperations {
// ...
    public static Detection readDetection(Path p) {
        try {
            List<String> lines = Files.readAllLines(p);
// etc ...

I'm partially convinced that the problem lies with my having incorrectly compiled the jar, but since I'm a complete novice at this sort of thing I don't know how to check I'm doing it right. Does anyone have any advice?

Answer 1

You're trying to use java.nio.file.Files.readAllLines(Path) , which was introduced in Java 8. You're not going to be able to use that in Java 7.

Options:

• Upgrade to Java 8 on the raspberry pi
• Don't use any classes/methods which are specified to Java 8. (Change your Eclipse project to target a Java 7 JRE to enforce this)

As it happens, the overload of readAllLines which takes a Path and a Charset is available on Java 7, and that's a better overload to use anyway, so that you're explicit about which encoding you want to use. So change your code to:

// Or whichever Charset you really want...
List<String> lines = Files.readAllLines(p, StandardCharsets.UTF_8);

Answer 2

Rasberry Pi可能具有Java ME（微型版），它不包含Java SE（标准版）中运行Eclipse的计算机上可能具有的许多方法。