1、创建实体类
package com.groovy.model
/**
* 在Groovy不需要自定义构造方法.但是必须要指定属性名称去传参数数据,Groovy会自动创建，在调用的时候会自动生成setter/getter方法
*/
class User implements Serializable{
//用户Id
Long userId
//用户名
String userName
//年龄
int age
}
2、创建测试test.txt文件
- 在工程的Resource资源文件夹里面创建此文件即可在程序读取，文件内容有自己指定.
A multi-faceted language for the Java platform
Apache Groovy is a powerful, optionally typed and dynamic language, with static-typing and static compilation capabilities,for the Java platform aimed at improving developer productivity thanks to a concise, familiar and easy to learn syntax.
It integrates smoothly with any Java program, and immediately delivers to your application powerful features, includingscripting capabilities, Domain-Specific Language authoring, runtime and compile-time meta-programming and functional programming.
2、测试类
package com.groovy.domain
import com.groovy.model.User
import org.junit.Test
class FileTest {
@Test
void testReader1() {
//直接读取项目resource目录的指定文件名称
def baseDir = FileTest.getClassLoader().getResource("test.txt").getPath()
/**
* 循环读取每一行进行读取.
*/
new File(baseDir).eachLine { line, nb ->
println "Line $nb: $line"
}
}
@Test
void testReader2() {
//指定路径目录,在指定文件名进行读取，此时的路径必须要知道在哪里
def baseDir = "D:/devsoft/idea-workspace/groovy/out/production/resources/"
/**
* 循环读取每一行进行读取.
*/
new File(baseDir, "test.txt").eachLine { line, nb ->
println "Line $nb: $line"
}
}
@Test
void testReader3() {
//直接读取项目resource目录的指定文件名称
def baseDir = FileTest.getClassLoader().getResource("test.txt").getPath()
/**
* 一次性获取文件所有内容，并指定编码
*/
def fileText = new File(baseDir).getText("utf-8")
println(fileText)
}
@Test
void testWriter1() {
// 此时会在项目工程的groovy/out/production/resources/目录先对test.txt文件操作
// 建议指定一个磁盘目录,然后在指定文件名称进行写入,如：testWriter2
def baseDir = FileTest.getClassLoader().getResource("test1.txt").getPath()
/**
* 循环读取每一行进行读取.
*/
new File(baseDir).withWriter("utf-8") { writer ->
writer.writeLine 'Hello Groovy'
}
}
@Test
void testWriter2() {
def baseDir = "D:/test/"
/**
* 指定一个磁盘文件目录，并且指定一个文件test1.txt名称进行写入内容
*/
new File(baseDir, "test1.txt").withWriter("utf-8") { writer ->
writer.writeLine 'Hello Groovy'
}
}
/**
* 拷贝文件内容,从一个文件拷贝内容到另外一个文件
* @param sourcePath
* @param dstPath
*/
def copyFile(String sourcePath, String dstPath) {
try {
//判断不存在就,创建文件目录
def dstFile = new File(dstPath)
if (!dstFile.exists()) {
dstFile.createNewFile()
}
//开始拷贝
new File(sourcePath).withReader { reader ->
//一次性读取所有信息
def lines = reader.readLines()
//写入目标文件
dstFile.withWriter { writer ->
lines.forEach { line ->
//写入目标文件并且换行
writer.append(line).append("\r\n")
}
}
}
return true
} catch (Exception ex) {
ex.printStackTrace()
}
return false
}
/**
* 保存Object
* @param obj
* @param path
*/
def saveObject(Object obj, String path) {
try {
def dstFile = new File(path)
if (!dstFile.exists()) {
dstFile.createNewFile()
}
dstFile.withObjectOutputStream {
it.writeObject(obj)
}
return true
} catch (Exception ex) {
ex.printStackTrace()
}
return false
}
/**
* 读取对象数据
* @param path
*/
def readObject(String path) {
def obj = null
try {
def dstFile = new File(path)
if (dstFile == null || !dstFile.exists()) return null
//读取对象数据出来
dstFile.withObjectInputStream {
obj = it.readObject()
}
} catch (Exception ex) {
ex.printStackTrace()
}
return obj
}
@Test
void testReaderObject() {
//读取出来并转换成User对象，语法与Kotlin类似
def user = readObject("user.bin") as User
println("userName=${user.userName},age=${user.age}")
}
@Test
void testWriterObject() {
def result = saveObject(user, "user.bin")
println(result ? "成功" : "失败")
}
}
3、testReader1与testReader2运行的结果
-
image.png
4、testWriter1与与testWriter2运行的结果
-
image.png
5、testWriterObject运行的结果
image.png
6、testReaderObject运行的结果
userName=周伯通,age=110
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