Spring SimpleCommandLinePropertySource

  • 全路径: org.springframework.core.env.SimpleCommandLinePropertySource
  1. public class SimpleCommandLinePropertySource extends CommandLinePropertySource<CommandLineArgs> {}
  • SimpleCommandLinePropertySource 的 source 类型是 CommandLineArgs 具体解释请看下面分析

CommandLineArgs

两个内部属性

  1. class CommandLineArgs {
  2.     /**
  3.      * 选项参数列表
  4.      */
  5.     private final Map<String, List<String>> optionArgs = new HashMap<>();
  7.     /**
  8.      * 非选项参数列表
  9.      */
  10.     private final List<String> nonOptionArgs = new ArrayList<>();
  12. }

addOptionArg

添加 选项参数

  1. public void addOptionArg(String optionName, @Nullable String optionValue) {
  2.    if (!this.optionArgs.containsKey(optionName)) {
  3.       this.optionArgs.put(optionName, new ArrayList<>());
  4.    }
  5.    if (optionValue != null) {
  6.       this.optionArgs.get(optionName).add(optionValue);
  7.    }
  8. }

getOptionNames

  • 获取选项参数列表
  1. public Set<String> getOptionNames() {
  2.    return Collections.unmodifiableSet(this.optionArgs.keySet());
  3. }
  • 其他方法不具体描述了，各位可以查看下面的代码
  1. class CommandLineArgs {
  3.    /**
  4.     * 选项参数列表
  5.     */
  6.    private final Map<String, List<String>> optionArgs = new HashMap<>();
  8.    /**
  9.     * 非选项参数列表
  10.     */
  11.    private final List<String> nonOptionArgs = new ArrayList<>();
  13.    /**
  14.     * Add an option argument for the given option name and add the given value to the
  15.     * list of values associated with this option (of which there may be zero or more).
  16.     * The given value may be {@code null}, indicating that the option was specified
  17.     * without an associated value (e.g. "--foo" vs. "--foo=bar").
  18.     *
  19.     * 添加 选项参数
  20.     */
  21.    public void addOptionArg(String optionName, @Nullable String optionValue) {
  22.       if (!this.optionArgs.containsKey(optionName)) {
  23.          this.optionArgs.put(optionName, new ArrayList<>());
  24.       }
  25.       if (optionValue != null) {
  26.          this.optionArgs.get(optionName).add(optionValue);
  27.       }
  28.    }
  30.    /**
  31.     * Return the set of all option arguments present on the command line.
  32.     * 获取选项参数列表
  33.     */
  34.    public Set<String> getOptionNames() {
  35.       return Collections.unmodifiableSet(this.optionArgs.keySet());
  36.    }
  38.    /**
  39.     * Return whether the option with the given name was present on the command line.
  40.     */
  41.    public boolean containsOption(String optionName) {
  42.       return this.optionArgs.containsKey(optionName);
  43.    }
  45.    /**
  46.     * Return the list of values associated with the given option. {@code null} signifies
  47.     * that the option was not present; empty list signifies that no values were associated
  48.     * with this option.
  49.     */
  50.    @Nullable
  51.    public List<String> getOptionValues(String optionName) {
  52.       return this.optionArgs.get(optionName);
  53.    }
  55.    /**
  56.     * Add the given value to the list of non-option arguments.
  57.     */
  58.    public void addNonOptionArg(String value) {
  59.       this.nonOptionArgs.add(value);
  60.    }
  62.    /**
  63.     * Return the list of non-option arguments specified on the command line.
  64.     */
  65.    public List<String> getNonOptionArgs() {
  66.       return Collections.unmodifiableList(this.nonOptionArgs);
  67.    }
  69. }

在了解 CommandLineArgs 类后再来看 SimpleCommandLinePropertySource 会相对容易. 内部的几个方法就是调用 CommandLineArgs 所提供的方法

  1. @Override
  2. public String[] getPropertyNames() {
  3.    return StringUtils.toStringArray(this.source.getOptionNames());
  4. }
  6. @Override
  7. protected boolean containsOption(String name) {
  8.    return this.source.containsOption(name);
  9. }
  11. @Override
  12. @Nullable
  13. protected List<String> getOptionValues(String name) {
  14.    return this.source.getOptionValues(name);
  15. }
  17. @Override
  18. protected List<String> getNonOptionArgs() {
  19.    return this.source.getNonOptionArgs();
  20. }