guava-test

import com.google.common.base.*;
import com.google.common.cache.*;
import com.google.common.collect.*;
import com.google.common.hash.*;
import com.google.common.hash.Hashing;
import com.google.common.io.Files;
import com.google.common.io.LineProcessor;
import org.junit.Assert;
import org.junit.Test;

import java.io.File;
import java.io.IOException;
import java.nio.charset.Charset;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;

/**
 * @author 玄畅
 * @date 5/23/14 23:28
 */
public class GuavaTest {
	@Test
	public void testOptional() {
		Optional<Long> possible = Optional.of(5l);
		Assert.assertTrue(possible.isPresent());
		Assert.assertEquals(possible.get().longValue(), 5l);

		String str = null;
		Optional<String> os = Optional.fromNullable(str);
		Assert.assertNull(os.orNull());
		Assert.assertEquals(os.or("aa"), "aa");
		System.out.println(os.or("lasdfjlasdjf"));

		//	返回两个中前面不为null的字符串
		String s = Objects.firstNonNull(null, "ss");
		Assert.assertEquals(s, "ss");
		System.out.println(s);
	}

	@Test
	public void testNullEmpty() {
		//	null -->  ""
		String s = Strings.nullToEmpty(null);
		Assert.assertEquals(s, "");

		//	""  -->  null
		String s2 = Strings.emptyToNull("");
		Assert.assertNull(s2);
	}

	@Test
	public void testPreconditions() {
		Preconditions.checkArgument(true);    //	IllegalArgumentException
		Preconditions.checkNotNull(null);
	}

	@Test
	public void testFunction() {
		//	把一个字符串列表，转化成只包含大写的字符串长度集合
		final Set<String> list = ImmutableSet.of("a", "LJSLDJF", "B", "asadfSDFas");
		Multiset<Integer> lengths = HashMultiset.create(
				FluentIterable.from(list)
						.filter(new Predicate<String>() {
							public boolean apply(String string) {
								//	检查条件，true检查通过
								return CharMatcher.JAVA_UPPER_CASE.matchesAllOf(string);
							}
						})
						.transform(
								new Function<String, Integer>() {
									public Integer apply(String string) {
										//	改变单个Item，返回新值
										return string.length();
									}
								}));

		//	得到转化的结果
		for (int len : lengths) {
			System.out.println(len);
		}
	}

	@Test
	public void testJoiner() {
		String baseUrl = "http://www.taobao.com/m?";
		ImmutableMap<String, String> map = ImmutableMap.of("a", "va", "b", "vb", "c", "vc");

		//	字符串拼接
		String r1 = Joiner.on("&").withKeyValueSeparator("=").join(map);
		System.out.println(baseUrl + r1);

		String r2 = Joiner.on("-").skipNulls().join("asdf", "", null, "2323");
		System.out.println(r2);
	}

	@Test
	public void testSplitter() {
		String url = "http://tiaoshi.taobao.com/?spm=1.7274553.1997517397.2.FAQPAH&acm=20140506001.1003.2.70913&ad_id=&cm_id=&pm_id=&am_id=130109847509e8c34b1b&uuid=79KoSnlA&scm=1003.2.20140506001.OTHER_1402811863232_70913&pos=0";
		Map<String, String> ret = Splitter.on("&").withKeyValueSeparator("=").split(url);
		for (Map.Entry<String, String> entry : ret.entrySet()) {
			System.out.println(entry.getKey() + ":" + entry.getValue());
		}
	}

	@Test
	public void testIO() throws IOException {
		File f = new File("/Users/shijinkui/tmp/ssltest.py");
		String ret = Files.readLines(f, Charset.defaultCharset(), new LineProcessor<String>() {
			StringBuffer sf = new StringBuffer();

			@Override
			public boolean processLine(String line) throws IOException {
				if (line.length() > 0) {
					sf.append(line).append("\n");
				}

				return true;
			}

			@Override
			public String getResult() {
				return sf.toString();
			}
		});

		System.out.println(ret);
	}

	@Test
	public void testHash() {
		//	支持的hash
		//	md5()	murmur3_128()	murmur3_32()	sha1()
		//  sha256()	sha512()	goodFastHash(int bits)
		HashFunction hf = Hashing.md5();
		HashCode hc = hf.newHasher()
				.putLong(System.currentTimeMillis())
				.putString("sjk", Charsets.UTF_8)
				.hash();

		System.out.println(hc.toString());
	}

	@Test
	public void testBloomFilter() {
		BloomFilter<Long> friends = BloomFilter.create(Funnels.longFunnel(), 500, 0.01);
		ImmutableList<Long> list = ImmutableList.of(1l, 2l, 2489234l, 1l);
		for (long friend : list) {
			friends.put(friend);
		}

		System.out.println(friends.mightContain(1l));
		System.out.println(friends.mightContain(2l));
		System.out.println(friends.mightContain(2489234l));
		System.out.println(friends.mightContain(1232l));
	}

	@Test
	public void testCache() throws ExecutionException, InterruptedException {
		LoadingCache<String, String> cache = CacheBuilder.newBuilder().softValues()
				.maximumSize(1000)
				.expireAfterWrite(2, TimeUnit.SECONDS)
				.recordStats()
				.removalListener(
						new RemovalListener<String, String>() {
							@Override
							public void onRemoval(RemovalNotification notify) {
								System.out.println("remove notify: " + notify.getKey() + "||"
										+ notify.getValue() + "||" + notify.getCause().toString());
							}
						})
				.build(new CacheLoader<String, String>() {
					public String load(String key) throws Exception {
						System.out.println("--->> reload:" + key);
						return key + "--" + System.currentTimeMillis();
					}
				});

		cache.put("1", "111");
		cache.put("2", "32323");
		cache.put("3", "asfasf");

		System.out.println(cache.get("1"));
		System.out.println(cache.getIfPresent("122"));

		Thread.sleep(3000);

		System.out.println(cache.get("1"));
		System.out.println(cache.stats().toString());

	}
}