25 lines
779 B
Java
25 lines
779 B
Java
package singleton;
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public class AppConfigEager {
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// The JVM creates this instance when the class is first loaded.
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// static guarantees it belongs to the class, not any instance.
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// final guarantees it can never be reassigned.
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private static final AppConfigEager INSTANCE = new AppConfigEager();
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// Private constructor: prevents any other class from calling new AppConfigEager()
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private AppConfigEager() {
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System.out.println("Reading configuration from file...");
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// load properties, set up values, etc.
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}
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// The only way to get the instance
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public static AppConfigEager getInstance() {
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return INSTANCE;
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}
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public String getProperty(String key) {
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return System.getProperty(key, "(not set)");
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}
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}
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