java写代码的一些小技巧

罗列并过滤目录下特定文件名

File dir = new File("/path/to/pdfs");
    File[] files = dir.listFiles(new FilenameFilter() {
        @Override
        public boolean accept(File dir, String name) {
            return name.matches("Comp_20120619_[^_]*_2_632128_FC_A_8_23903.pdf");
        }
    });

遍历文件夹，寻找指定文件

Iterator<File> stationFiles = FileUtils.iterateFiles(distributionFolder.getFile(),
                new WildcardFileFilter("*station.properties"),
                TrueFileFilter.INSTANCE);

Spring下注入Resource

import org.springframework.core.io.Resource;

@Value("classpath:<path to file>")
private Resource cert;

@Value("${some.property}")
private Resource sqlFile;

spring resource

用JSch实现FTP功能和bufferedstream用法

try {
	JSch jsch = new JSch();
	session = jsch.getSession(SFTPUSER, SFTPHOST, SFTPPORT);
	session.setPassword(SFTPPASS);
	java.util.Properties config = new java.util.Properties();
	config.put("StrictHostKeyChecking", "no");
	session.setConfig(config);
	session.connect();
	channel = session.openChannel("sftp");
	channel.connect();
	channelSftp = (ChannelSftp) channel;
	channelSftp.cd(SFTPWORKINGDIR);
	byte[] buffer = new byte[1024];
	BufferedInputStream bis = new BufferedInputStream(channelSftp.get("Test.java"));
	File newFile = new File("C:/Test.java");
	OutputStream os = new FileOutputStream(newFile);
	BufferedOutputStream bos = new BufferedOutputStream(os);
	int readCount;
	// System.out.println("Getting: " + theLine);
	while ((readCount = bis.read(buffer)) > 0) {
		System.out.println("Writing: ");
		bos.write(buffer, 0, readCount);
	}
	bis.close();
	bos.close();
} catch (Exception ex) {
	ex.printStackTrace();
}

Spring MVC 单元测试

@ContextConfiguration(locations = {"classpath:/spring/test-webapp-config.xml"})
@WebAppConfiguration
public class StationControllerTest extends AbstractJUnit4SpringContextTests
{
    public static final MediaType APPLICATION_JSON_UTF8 = new MediaType(MediaType.APPLICATION_JSON.getType(),
        MediaType.APPLICATION_JSON.getSubtype(), Charset.forName("utf8"));
        
    @Mock
    private StationService stationServiceMock;
    
    @Autowired
    private WebApplicationContext wac;
    
    private MockMvc mockMvc;
    
    @Before
    public void setup()
    {
        // Process mock annotations
        MockitoAnnotations.initMocks(this);
        
        // Setup Spring test in standalone mode
        this.mockMvc = webAppContextSetup(this.wac).build();
        //standaloneSetup(stationController).build();
    }
    
    @Test
    public void findAll_ShouldAddStationEntriesToModelAndRenderStationListView()
        throws Exception
    {
        // given
        Station station = new Station();
        station.setId("wz");
        station.setStationName("wenzhou");
        station.setFtpIp("192.168.0.19");
        station.setFtpPort(22);
        station.setFtpUser("hadoop");
        station.setFtpPwd("hadoop");
        station.setSshIp("192.168.0.113");
        station.setSshPort(21);
        station.setSshUser("hadoop");
        station.setSshPwd("hadoop");
        
        // when
        when(stationServiceMock.getAllStations()).thenReturn(Arrays.asList(station));
        
        // then
        
        //@formatter:off
        mockMvc.perform(get("/stations/stationlist.json"))
        .andExpect(status().isOk())
        .andExpect(content().contentType(APPLICATION_JSON_UTF8));
        //.andExpect(jsonPath("$", hasSize(1)));
        //@formatter:on
        
        verify(stationServiceMock, times(1)).getAllStations();
        verifyNoMoreInteractions(stationServiceMock);
    }
}

Spring初始化 Map in bean xml

<bean id="launcherContext" class="com.pip.launcher.impl.LauncherContext">
	<constructor-arg>
		<util:map>
		  <entry key="#{T(com.pip.common.model.enumfactory.ServerType).Account}" value="${Account}" />
		  <entry key="#{T(com.pip.common.model.enumfactory.ServerType).Data}" value="${Data}" />
		  <entry key="#{T(com.pip.common.model.enumfactory.ServerType).Upload}" value="${Upload}" />
		  <entry key="#{T(com.pip.common.model.enumfactory.ServerType).Collect}" value="${Collect}" />
		  <entry key="#{T(com.pip.common.model.enumfactory.ServerType).Fence}" value="${Fence}" />
		  <entry key="#{T(com.pip.common.model.enumfactory.ServerType).Collision}" value="${Collision}" />
		  <entry key="#{T(com.pip.common.model.enumfactory.ServerType).Call}" value="${Call}" />
		  <entry key="#{T(com.pip.common.model.enumfactory.ServerType).Web}" value="${Web}" />
		</util:map>
	</constructor-arg>
</bean>

weblogic 检查状态

java -cp C:\ Oracle\Middleware\wlserver_10.3\server\lib\weblogic.jar   weblogic.Admin -adminurl localhost:7001 -username weblogic -password weblogic1 GETSTATE

spring mvc 的request mapping中路径包含 `.` 的解析

@RequestMapping("/openLog/{stationId}/{serverType}/{logName:.+}")

GBK 编码

Charset.forName("GBK")

多线程并发eventbus

private final EventBus sendEvent = new AsyncEventBus("send", Executors.newFixedThreadPool(4));
    @Subscribe
    @AllowConcurrentEvents
    public void sendStringMessage(String message)
    {
        Result result = distirbution.newMessage(message);
        if (result.issuccess())
        {
            sendLabel.setText(String.format(sendStatusFormat, sendTimes.get(), successTimes.incrementAndGet()));
        }
    }

随机生成指定范围大小的bytes数组

private byte[] createRandomBytesWithSpecifiedSize()
        {
            // Random sized file (from 1 MB to say 3 MB)
            int min = 1024 * 1024 * 1;
            int max = 1024 * 1024 * 3;
            int size = new Random().nextInt(max - min + 1) + min;
            byte[] bytes = new byte[size];
            new Random().nextBytes(bytes);
            return bytes;
        }

dubbo 单元测试

export dubbo某一服务

   private <T> void exportServer(T server, int port)
    {
        ProviderConfig provider = new ProviderConfig();
        ServiceConfig<T> service = new ServiceConfig<T>();
        service.setProvider(provider);
        service.setProtocol(new ProtocolConfig("dubbo", port));
        service.setApplication(new ApplicationConfig("provider"));
        service.setRegistry(new RegistryConfig(RegistryConfig.NO_AVAILABLE));
        service.setInterface(server.getClass().getInterfaces()[0]);
        service.setRef(server);
        service.export();
    }

并发执行并等待，有直接返回，至最大等待时间

private Boolean consoleOutputIsRunning(final Process process, int timeout)
    {
        ExecutorService executor = Executors.newSingleThreadExecutor();
        CompletionService<Boolean> completionService = new ExecutorCompletionService<Boolean>(executor);
        completionService.submit(new Callable<Boolean>()
        {
            @Override
            public Boolean call()
                throws InterruptedException
            {
                if(xxxxx) {
                    return true;
                }
        });
        
            Future<Boolean> resultFuture = completionService.poll(timeout, TimeUnit.SECONDS);
            if (resultFuture != null)
            {
                Boolean result = resultFuture.get();
                if (result != null)
                {
                    return result;
                }
            }
        return Boolean.FALSE;
    }

spring jpa 中字段使用joda time

@Column(name = "DJRQ") // 登记日期
@Type(type = "org.jadira.usertype.dateandtime.joda.PersistentLocalDate")
private LocalDate registrationDate;

Spring 从属性文件中直接读取值

@Value("${highRisk.district.age.max}")
private int maxLimitedAge;

@Value("${highRisk.district.age.min}")
private int minLimitedAge;

@Value("#{'${highRisk.district.list}'.split(',')}")
private List<String> highRiskDistricts;

当spring 中要用 @Value annotations 去拿值时需要在 config类（@Configuration）中添加以下方法

 @Bean
    public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
        return new PropertySourcesPlaceholderConfigurer();
    }

在spring test中使用spy

    @Spy
    private XwallServiceImpl xwallService;

    Mockito.doReturn(new Long(1)).when(xwallService).countDateZZRKRegistration(today);

H2 Database 在测试中添加方法 functions

public class Function {
    public static int isMan(String value) {
        return 1;
    }
}

@Autowired
private DataSource dataSource;

@Before
public void setup() throws Exception {
	Connection conn = dataSource.getConnection();
	Statement st = conn.createStatement();
	st.execute("CREATE ALIAS IS_MAN FOR \"com.pip.xwall.Function.isMan\"");
	st.close();
	conn.close();
}

测试中如何申明有序集合里各元素匹配

assertThat(newList, IsIterableContainingInOrder.<Number> contains(2L, 3L, 4L, 5L, 6L, 7L, 8L));

spring data jpa 自动生成序列号

@Id
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator="judgements_id_seq")
@SequenceGenerator(name="judgements_id_seq", sequenceName="judgements_id_seq", allocationSize=1)
@Column(name = "JUD_ID")
private Long _judId;

使用POI 对excel进行读操作

导入包

<dependency>
	<groupId>org.apache.poi</groupId>
	<artifactId>poi</artifactId>
</dependency>
<dependency>
	<groupId>org.apache.poi</groupId>
	<artifactId>poi-excelant</artifactId>
	<version>3.10.1</version>
</dependency>
<dependency>
	<groupId>org.apache.poi</groupId>
	<artifactId>poi-ooxml</artifactId>
	<version>3.10.1</version>
</dependency>

读操作

try {
	Resource resource = new ClassPathResource("data/xwall-12-months.xlsx");
	XSSFWorkbook workbook = new XSSFWorkbook(resource.getInputStream());
	XSSFSheet sheet = workbook.getSheet("Sheet3");
	Iterator<Row> rowIterator = sheet.rowIterator();
	if (rowIterator.hasNext())
		rowIterator.next();// zzrk
	if (rowIterator.hasNext())
		rowIterator.next();// column name
	while (rowIterator.hasNext()) {
		Row dataColumn = rowIterator.next();

		if (dataColumn.getCell(zzrkCriminalDate) != null && dataColumn.getCell(zzrkCriminalValue) != null) {
			dataColumn.getCell(zzrkCriminalValue).setCellType(Cell.CELL_TYPE_STRING);
			zzrkExcelData.add(new ExcelData(ZZRK, dataColumn.getCell(zzrkCriminalDate).getDateCellValue(), CRIMINAL,
					dataColumn.getCell(zzrkCriminalValue).getStringCellValue()));
		}
	}
}
catch (FileNotFoundException e) {
	// TODO Auto-generated catch block
	e.printStackTrace();
}
catch (IOException e) {
	// TODO Auto-generated catch block
	e.printStackTrace();
}

spring test中使 db transaction生效

test 类加上以下标注：

@RunWith(SpringJUnit4ClassRunner.class)
@Transactional
@TransactionConfiguration(transactionManager = "xxxxx", defaultRollback = true)

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java写代码的一些小技巧

[目录]

罗列并过滤目录下特定文件名

遍历文件夹，寻找指定文件

Spring下注入Resource

用JSch实现FTP功能和bufferedstream用法

Spring MVC 单元测试

Spring初始化 Map in bean xml

weblogic 检查状态

spring mvc 的request mapping中路径包含 . 的解析

GBK 编码

多线程并发eventbus

随机生成指定范围大小的bytes数组

dubbo 单元测试

并发执行并等待，有直接返回，至最大等待时间

spring jpa 中字段使用joda time

spring mvc 的request mapping中路径包含 `.` 的解析

H2 Database 在测试中添加方法 functions