在地图中存储属性文件

Question

I want to read a usual properties file and put the attribute and his value into a Map object. Technically, a properties file like

attr1=hello
attr2=java
attr3=world

would dynamically become a map object like this

+-------+-------+
+   K   |   V   +
+-------+-------+
+ attr1 | hello +
+-------+-------+
+ attr2 | java  +
+-------+-------+
+ attr3 | world +
+-------+-------+

In the end, it shouldn't matter what's in the properties file, the whole file will just be saved as a Map. Is it possible to do that with java.Properties or is a FileReader or an InputStream with special parsing necessary?

Answer 1

java.util.Properties also implements of Map .

To load the properties from file, use Properties' load() method with Reader or InputStream .

For instance,

Properties config = new Properties();
try {
    config.load(<this.class>.getResourceAsStream(<property-file-name>)); //example input stream
    //now can access it as a Map instance
    config.get(<Key>);
    config.entrySet();

    //additionally, you can access Properties methods
    config.getProperty(<property-name>);

} catch(...) {
    ...
}

If you want only Map instance, let's say kind of Map<String, String> , need to convert the properties to required map instance by iterating the property names.

Properties config = new Properties();
try {
    config.load(<this.class>.getResourceAsStream(<property-file-name>)); //exampl input stream

    Map<String, String> map = new HashMap<String, String>();
    for (final String name: config.stringPropertyNames())
        map.put(name, config.getProperty(name));

} catch(...) {
    ...
}