oracle java api

The Java Reflection API provides insight into the classes, interfaces, and objects in the JVM. Developers often use APIs to accomplish the following tasks, which explains why they always use development tools, such as debugger and integrated Development environments (IDEs): · Determines the class of an object. · Get information about a class of modifiers, fields, methods, constructors, etc. · Gets the co

Windows OS users are familiar with Excel (workbooks), but it is not easy to use Java to manipulate Excel files. As web applications are becoming increasingly popular today, the demand for using web to Operate Excel files is getting stronger and stronger. Currently, a popular operation is to create a CSV (comma separated values) file in JSP or servlet, the file is returned to the browser as mime, text/CSV, and then the browser calls Excel and displays

Java ee 7 API version specification Eclipse4.3 supports javaee7 specifications:A series of specifications: J2EE is a platform composed of a series of technical standards, including: ? Applet-Java Applet? EJB-Enterprise-level JavaBean (Enterprise Java Beans)? JAAS-Java Authen

string following the integer argumentstr.substring (int A, int b);//Take a string between A and B (not including B)StringBuffer (with buffers) are used primarily to build strings*stringbuffer append (char c)//AppendStringBuffer Insert (int offset, string str)//Inserts a string at an index locationStringBuffer deletecharat (int index)StringBuffer Delete (int start, int end)StringBuffer replace (int start, int end, String s)StringBuffer setcharat (int index, char ch)String toString ()StringBuffer

. Parse data 1.2.4. Output data 1.2.5. Releasing resources 2. Datagram Packet classThis class, which means "datagram packets", is used to implement a no-connection packet delivery service. Datagrampacket Construction Method Transceiver Structuring method formats Parameters Description Send Public Datagrampacket (byte[] buf, int len, inetaddress add, int port) BUF, send out the data Construct object used to send packet

); Desc.put ("ByteSize", 0l); NewThread (NewRunnable () {@Override Public voidrun () {//TODO auto-generated Method Stub while(true) { Try{Thread.Sleep (500); System.out.printf ("Maxl:%d\tcurrent:%d\tsurplus:%d\tprogressbar:%s\n", Desc.get ("ByteSize"), Desc.get ("current"), Desc.get (" ByteSize ")-desc.get (" current "), Df.format ((Desc.get (" current ") +0.0)/desc.get (" ByteSize "))); } Catch(interruptedexception e) {//TODO auto-generated Catch blockE.prints

(); LongThen, according to the primary key to update the ES information, which does not appear in the field to update, do not overwrite the original value.Updateresponse response = ElasticsearchConfig.client.prepareUpdate ("index", "type", "PRIMARY Key ID") . Setdoc ( Xcontentfactory.jsonbuilder (). startobject () field ("business Field 1", "2") . Field ("Busine

and writes its contents of 第101-120 bytes to the local file system Import Org.apache.hadoop.conf.configuration;import Org.apache.hadoop.fs.filesystem;import Org.apache.hadoop.fs.path;import Org.apache.hadoop.io.ioutils;import Java.io.bufferedoutputstream;import Java.io.file;import Java.io.fileoutputstream;import Java.io.inputstream;import Java.io.OutputStream;import Java.net.uri;public class Outputtest {public static void main (string[] args) {try {String dst = ar Gs[0]; S

=NewGetquery (); Query.setid ("1");//The ID of the index Yanan Yanan = elasticsearchtemplate.queryforobject (query, Yanan.Class); System.out.println (Yanan.getgender ()); System.out.println (Yanan.getname ()); System.out.println (Yanan.getid ());//ID of the entity}Static Elasticsearchtemplate getelasticsearchtemplate (String ip,string clustername,int port) {//http://blog.csdn.net/ty4315/article/details/52434296"target=" _blank ">@ reference article 1http://blog.csdn.net/ljc2008110/article/detai

:" + Collectmaxby.get ()); // Print Results // Collectmaxby:4Split data block: Collectors.partitioningbyMap) (it% 2 = 0)); System.out.println ("Collectparti:" + Collectparti); // Print Results // Collectparti: {false=[1, 3], true=[2, 4]}Data group: Collectors.groupingbyMap) (It > 3)); System.out.println ("Collectgroup:" + collectgroup); // Print Results // Collectgroup: {false=[1, 2, 3], true=[4]}String: collectors.joiningString Strjoin = Stream.of ("1", "2", "3", "4")

Aggregation operations reducet reduce (t identity, Binaryoperator Accumulator)Code:int value = Stream.of (1, 2, 3, 4). Reduce (sum, item), sum + item);Or use a method reference:int value = Stream.of (1, 2, 3, 4). Reduce (+, integer::sum);Value results: 101,103,106,110Identity: It allows the user to provide an initial value for a loop calculation. (+)ACCUMULATOR: The computed accumulator, whose method signature is apply (T t,u u), in which the first parameter T(SUM) is the return value of the las

hadmin.disabletable (tableName); hadmin.deletetable (TableName); System.out.println ("Delete table" +tablename+ "Success!" ");} else {System.out.println ("Deleted Tables" +tabLename+ "does not exist! "); System.exit (0);}} Add a data public static void AddRow (String tableName, String row,string columnfamily, string column, String value) throws E xception {htable table = new htable (conf, tableName); Put put = new put (bytes.tobytes (row));//Specify Rows//Parameters: Column family, column, Valu

representation and converted to a decimal System.out.println (Integer.parseint ("3C", 16));}}Automatic packing and unpackingpublic class Main {public static void main (string[] args) {integer a = new Integer ("3"); integer b = new Integer (3); System.out.println (A = = B);//Two new addresses must be different System.out.println (A.equals (b));//equals compares content System.out.println ( A.compareto (b)); int num = 5;num++;integer Xinteger = 5;//xinteger = new Integer (5), auto boxing Xinteger

Java.util.hashmap;import java.util.iterator;import Java.util.map;import Java.util.scanner;import Java.util.treemap;import Javax.management.runtimeerrorexception;public class Main {public static void Main (string[] args) {/* The application of Map collection in table-checking method is more */int num; Scanner in = new Scanner (system.in); num = In.nextint (); String week = Get_week (num-1); SYSTEM.OUT.PRINTLN (week); System.out.println (Get_week_english (Week)); In.close ();} public static Strin

stubif (!) arg0 instanceof Man) throw new ClassCastException (); Man mans = (man) arg0;int te = This.age-man.age;return te==0?this.name.compareto (man.name): TE;}} Iii. Practice: The application of comparatorsTo sort a string in lengthImport Java.util.comparator;import Java.util.iterator;import Java.util.treeset;class ComparatorLengh implements Comparator{public int Compare (object arg0, Object arg1) {//TODO auto-generated method stubstring str0 = (String) arg0; String str1 = (string) arg1;int

diff = ChronoUnit.SECONDS.between (localDate1, LocalDate2);Formatting DateTimeFormatter DateTimeFormatter = Datetimeformatter.ofpattern ("Yyyy-mm-dd"); = Datetimeformatter.format (localdate);Two dates are equal Boolean b = localdate1.equals (LOCALDATE2);LocalTimeMost APIs are the same as localdate, where the difference is1, cannot judge whether leap year2.Localdate Object ToString () returns "2017-11-09", LocalTime object ToString () returns "11:16:50.144" (if the number of millisecon

result set. SetSize (1000)//sets whether to sort by query matching. Setexplain (TRUE)///finally return to the search ring should be information. Execute (). Actionget (); Searchhits searchhits=response.gethits ();//System.out.println ("-----------------in [" +term+ "] Search for keywords [" +querystring +"]---------------------"); System.out.println (System.currenttimemillis ()-L); System.out.println ("co-match to:" +searchhits.gettotalhits () + "strip record!");

processing index. If you need to put a string as a whole to be indexed, this field needs to be set: Field ("Index", "not_analyzed").Index data /** * Bulk Index */@Test public void Indexdata () {Bulkrequestbuilder Requestbuilder = Client.preparebu LK (); for (person person:personlist) {String obj = getindexdatafromhotspotdata (person); if (obj! = null) {Requestbuilder.add (Client.prepareindex ("Test_index", "Test", String.valueof (Person.getid ())) . Setrefresh (T

example one: exception handling mechanism in/** * java * @author Administrator * * */public class ExceptionDemo1 {public static VO ID Main (string[] args) {System.out.println ("program started"); try{String str = null; * * The JVM found STR null when executing the Str.length () method. * Then create a nullpointerexception instance, encapsulate the description of the error, and then throw out the exception. * The JVM then looks at whether

The example of this article for everyone to share the Java monthly Shipping API call code for your reference, the specific contents are as follows Import Java.io.BufferedReader; Import Java.io.DataOutputStream; Import java.io.IOException; Import Java.io.InputStream; Import Java.io.InputStreamReader; Import java.io.UnsupportedEncodingException; Import java.net.HttpURLConnection; Import Java.net.URL; I