SE carding
1. Data Type
1. Basic type
7. char (default: '\u0000')
8. boolean (default: false)
Numerical
Integer (default: 0)
1. byte
2. short
3. int
4. long (add suffix L)
decimal, float (default: 0.0)
5. float (add suffix F)
6. double
2. Reference types
1. Class
2. Interface
3. Abstract class
4. Enumeration
5. Arrays
1. Statement
1. Static creation: datatype[] arrayname = {value1, value2. . . }
2. Dynamic creation: data type [] array name = new data type [length];
If you know the specific value, use static, and if you don't know the static value, use dynamic creation
2. Assignment
3. Value
4. Traverse
Design classes and create objects
1. Design class
package
1. private modifier member variable
2. Provide a getter and setter method for each member variable
this
3. Provide a no-argument constructor
Argumentary constructs can be provided depending on the situation
4. The public modification of this class
eclipse automatically generated
inherit
Method Override @Override
1. hashCode() returns the hash value of the object
2. toString() prints the specified format of the object
3. equals(Object obj) Determine whether the values of two object member variables are equal according to the actual business
4. getClass() returns the bytecode file corresponding to the object
eclipse automatically generated
accomplish
super
Method overloading
Method Override @Override
method
variable parameter
abstract method
2. Create the object
1. Ordinary way
2. Polymorphism
3. Assignment
1. Constructs with parameters
2. setXxx(parameter)
Generally used in combination, there are few member variables, and it is constructed with parameters.
4. Value
getXxx();
2. Structure (flow control statement)
1. Conditional Statements
1. Single condition
2. Dual condition
3. Multi-condition
4. switch
2. Loop Statement
1. while
2. do while
3. for(){}
forfor
4. foreach
3. Loop Control Statement
1. break
2. continue、
3. return
3. Operation
1. Arithmetic operations
1. ++
1. ++a
2. a++
2. --
2. Assignment operation
3. Comparison operation
4. Logical Operations
5. Trinocular operation
6. Bit operations (understand)
4. Variables
1. Local variables
2. Member variables (fields)
1. Instance variables
2. Class variables
5. API usage
Common class
1. Numerical correlation class
1. 8 wrapper classes
2. Mathematics related
1. Math
2. BigInteger
3. BigDecimal
2. String related classes
1. String
2. StringBuffer
3. StringBuilder
Default 16, expansion *2+2
3. Date related classes
1. Date
1 LocalDate
2. LocalDateTime
3. ZonedDateTime: Time zone date and time
4. LocalTime: local time
Get object call via static method
2. Calendar
3. SimpleDateFormat
4. Tools
1. System
1. arraycopy(....)
2. currentTimeMillis()
2. Get random numbers
1. Random.nextInt()
3. ThreadLocalRandom
UUID
5. Exception class
1. try - catch -finally
2. throws
3. Custom exception
6. Thread
1. Create a thread 2 in the way
2. Thread synchronization
1. Synchronized code blocks
2. Synchronization method
3. ReentrantLock
3. Thread pool
4 Deadlock
5. Thread Communication
6. Timer related classes
1. Timer class
2. TimerTask [abstract class]
To understanding
7. Data Structures
Collection interface [single element]
1. List
1. ArrayList
2.LinkedList
3.Vector
2. Set
HashSet
TreeSet
LinkedHashSet
3. Map
1. HashMap
2. TreeMap
3. Hashtable
Properties
how to get stream
1. Via the current class bytecode file
2. through the current class classloader
3. class loader via thread
5. LinkedHashMap
6. ConcurrentHashMap
4. Generics
1. Generic class
2. Generic methods
3. Upper and Lower Limits
4. Nesting
scenes to be used
8. Stream
1. File file, folder class
Get next-level subfolders, subfiles
1. list()
2. listFiles()
3. list(FilenameFilter filter)
4. listFiles(FilenameFilter filter)
5. listFiles(FileFilter filter)
recursion
2. I.
1. Byte stream
1. OutputStream
FileOutputStream
2. InputStream
FileInputStream
2. Character stream
Reader
FileReader
Writer
FileWriter
3. Transform Streams
InputStreamReader
OutputStreamWriter
4. Buffered Streams
character buffer stream
1. readLine()
2. newLine()
5. Random file access class RandomAccessFile
6. Object Streams
9. Reflection
1. Get bytecode
1. get field
1. assign a value to a field
2. field value
2. get constructor
create object
3. get normal method
execution method
10. Notes
1. Four yuan annotations
1。 @Target
2。@Retention
3。 @Documented
4. @Inherited
2. Custom annotations
1. new an Annotation annotation class
2. Use the four meta-annotations on annotations
3. Declare properties in annotations
1. Supported data types
1。 String
2. 8 basic types
3. Enumeration class
4. array
3. Use annotations
1. @annotation name(attribute name=value)
2. @AnnotationName(AttributeName={value1, value2...})
11. New features of jdk8
1. lambda
2. Method reference in lambda
1. Static method: class name::static method name
2. Constructor: class name::new
3. Instance method: object name::instance method name
4. Special method: class name::instance method name
3. Stream stream method
4. Optional class [solves the problem of null values]
12. Test packaging tools
1. Unit testing @Test
2. jar import and export
13. Design Patterns
1. singleton pattern
1. Hungry Man Mode
2. lazy mode
3. enumerate
2. Simple Factory Pattern
3. Adapter Mode
4. decorator pattern
5. Observer pattern
6. Factory pattern. . . .
To understanding
14. xml parsing
5 ways
1. Dom4J parsing
1. Guide package
1. dom4j package
2. xpath uses beta package
2. Specific steps
1. Get the document object Document
2. Get the root element Element: rootElement
3. Add, delete, modify and check operations
15. JDBC [java connection database technology]
Database DBMS
Relational Database
1. mysql
1. DQL
1. Single table query
2. Multi-table query
1. Inner join
2. Outer join
left outer join
right outer join
self-connection
3. Subquery [nested query]
2. DDL
Create/drop tables, libraries
3. DML
Additions, deletions and modifications
4. Deleting the database and running away: backup and recovery
2. Oracle
non-relational database
1. Redis
2. Lucene
3. MongoD
Java summary
Guess you like
Origin http://10.200.1.11:23101/article/api/json?id=326832623&siteId=291194637
Recommended
Ranking