Java配置文件分段读取工具类

以下是一个Java配置文件分段读取的工具类，可以将配置文件按照section分段读取，每个section中的键值对以Map的形式存储：

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

public class ConfigParser {
    private String filename;
    private Map<String, Map<String, String>> sections;

    public ConfigParser(String filename) throws IOException {
        this.filename = filename;
        this.sections = new HashMap<>();
        parse();
    }

    public String get(String section, String option) {
        Map<String, String> options = sections.get(section);
        if (options != null) {
            return options.get(option);
        }
        return null;
    }

    public void set(String section, String option, String value) {
        Map<String, String> options = sections.computeIfAbsent(section, k -> new HashMap<>());
        options.put(option, value);
    }

    private void parse() throws IOException {
        try (BufferedReader br = new BufferedReader(new FileReader(filename))) {
            String line;
            String section = null;
            Map<String, String> options = new HashMap<>();
            while ((line = br.readLine()) != null) {
                line = line.trim();
                if (line.matches("\\[.*\\]")) {
                    if (section != null) {
                        sections.put(section, options);
                    }
                    section = line.substring(1, line.length() - 1);
                    options = new HashMap<>();
                } else if (line.matches(".*=.*")) {
                    String[] parts = line.split("=", 2);
                    String option = parts[0].trim();
                    String value = parts[1].trim();
                    options.put(option, value);
                }
            }
            if (section != null) {
                sections.put(section, options);
            }
        }
    }
}

使用示例：

public static void main(String[] args) throws IOException {
    ConfigParser config = new ConfigParser("config.ini");
    String value = config.get("section1", "option1");
    System.out.println(value);
    config.set("section2", "option2", "value2");
    // ...
}

其中，`config.ini`配置文件的格式如下：

[section1]
option1 = value1
option2 = value2

[section2]
option3 = value3
option4 = value4