Java Stream.count方法代碼示例

import java.util.stream.Stream; //導入方法依賴的package包/類
public static int countBandMembersExternal(List<Artist> artists) {
    // BEGIN COUNT_MEMBERS_EXTERNAL
int totalMembers = 0;
for (Artist artist : artists) {
    Stream<Artist> members = artist.getMembers();
    totalMembers += members.count();
}
    // END COUNT_MEMBERS_EXTERNAL

    return totalMembers;
}
 

import java.util.stream.Stream; //導入方法依賴的package包/類
private void loadDefaultAndActiveTheme()
{
	Optional<String> optionalDefaultThemePath =
			ApplicationSettings.getSetting(ApplicationSetting.APPLICATION_THEME);
	if ( !optionalDefaultThemePath.isPresent() )
	{
		throw new MissingResourceException(
				ApplicationSetting.APPLICATION_THEME.toString() + " was not present in settings.",
				this.getClass().getName(),
				ApplicationSetting.APPLICATION_THEME.toString());
	}

	//TODO Check if just name or ends with / \
	String tempPath = optionalDefaultThemePath.get();
	String defaultThemeDirectoryPath = (tempPath.endsWith("/|\\")) ? tempPath : tempPath + "/";
	String defaultThemeName = defaultThemeDirectoryPath.substring(0, defaultThemeDirectoryPath.length() - 1);
	String defaultThemePath = themeDirectory + defaultThemeDirectoryPath;

	//TODO ensure no duplicate theme names
	File defaultThemeDirectory = new File(defaultThemePath);
	if ( !defaultThemeDirectory.isDirectory() )
		throw new IllegalArgumentException(
				"Default theme directory was not a directory. Found: " + defaultThemeDirectory.getAbsolutePath());

	Stream<String> themeStream = themes.keySet().stream().filter(themeName -> themeName.equals(defaultThemeName));

	if ( themeStream.count() < 1 )
		throw new UnsupportedOperationException("Default theme not found.");

	themeStream = themes.keySet().stream().filter(themeName -> themeName.equals(defaultThemeName));

	defaultTheme = themes.get(themeStream.findFirst().get());

	//TODO load active/saved theme from settings file saved json object
}
 

import java.util.stream.Stream; //導入方法依賴的package包/類
private Archive newArchive(String module, Path path) {
    if (path.toString().endsWith(".jmod")) {
        return new JmodArchive(module, path);
    } else if (path.toString().endsWith(".jar")) {
        ModularJarArchive modularJarArchive = new ModularJarArchive(module, path);

        Stream<Archive.Entry> signatures = modularJarArchive.entries().filter((entry) -> {
            String name = entry.name().toUpperCase(Locale.ENGLISH);

            return name.startsWith("META-INF/") && name.indexOf('/', 9) == -1 && (
                        name.endsWith(".SF") ||
                        name.endsWith(".DSA") ||
                        name.endsWith(".RSA") ||
                        name.endsWith(".EC") ||
                        name.startsWith("META-INF/SIG-")
                    );
        });

        if (signatures.count() != 0) {
            if (ignoreSigning) {
                System.err.println(taskHelper.getMessage("warn.signing", path));
            } else {
                throw new IllegalArgumentException(taskHelper.getMessage("err.signing", path));
            }
        }

        return modularJarArchive;
    } else if (Files.isDirectory(path)) {
        return new DirArchive(path);
    } else {
        throw new IllegalArgumentException(
            taskHelper.getMessage("err.not.modular.format", module, path));
    }
}
 

import java.util.stream.Stream; //導入方法依賴的package包/類
void checkStreamState(Stream<StackFrame> stream) {
    try {
        stream.count();
        throw new RuntimeException("IllegalStateException not thrown");
    } catch (IllegalStateException e) {
        System.out.println("Got expected IllegalStateException: " + e.getMessage());
        e.printStackTrace(System.out);
    }
}
 

import java.util.stream.Stream; //導入方法依賴的package包/類
/**
 * Tests adding and removing connected switches.
 */
@Test
public void testAddRemoveConnectedSwitch() {

    // test adding connected switches
    boolean addSwitch1 = agent.addConnectedSwitch(dpid1, switch1);
    assertThat(addSwitch1, is(true));
    boolean addSwitch2 = agent.addConnectedSwitch(dpid2, switch2);
    assertThat(addSwitch2, is(true));
    boolean addSwitch3 = agent.addConnectedSwitch(dpid3, switch3);
    assertThat(addSwitch3, is(true));

    // Make sure the listener add callbacks fired
    assertThat(switchListener.addedDpids, hasSize(3));
    assertThat(switchListener.addedDpids, hasItems(dpid1, dpid2, dpid3));

    // Test adding a switch twice - it should fail
    boolean addBadSwitch1 = agent.addConnectedSwitch(dpid1, switch1);
    assertThat(addBadSwitch1, is(false));

    assertThat(controller.connectedSwitches.size(), is(3));

    // test querying the switch list
    Stream<OpenFlowSwitch> fetchedSwitches =
            makeIntoStream(controller.getSwitches());
    long switchCount = fetchedSwitches.count();
    assertThat(switchCount, is(3L));

    // test querying the individual switch
    OpenFlowSwitch queriedSwitch = controller.getSwitch(dpid1);
    assertThat(queriedSwitch, is(switch1));

    // Remove a switch
    agent.removeConnectedSwitch(dpid3);
    Stream<OpenFlowSwitch> fetchedSwitchesAfterRemove =
            makeIntoStream(controller.getSwitches());
    long switchCountAfterRemove = fetchedSwitchesAfterRemove.count();
    assertThat(switchCountAfterRemove, is(2L));

    // Make sure the listener delete callbacks fired
    assertThat(switchListener.removedDpids, hasSize(1));
    assertThat(switchListener.removedDpids, hasItems(dpid3));

    // test querying the removed switch
    OpenFlowSwitch queriedSwitchAfterRemove = controller.getSwitch(dpid3);
    assertThat(queriedSwitchAfterRemove, nullValue());
}