文件\流\字符串互转

1. import java.io.ByteArrayInputStream;
2. import java.io.ByteArrayOutputStream;
3. import java.io.File;
4. import java.io.FileInputStream;
5. import java.io.FileOutputStream;
6. import java.io.FileReader;
7. import java.io.FileWriter;
8. import java.io.IOException;
9. import java.io.InputStream;
10.  
11. import sun.misc.BASE64Decoder;
12.  
13. public class FileStrUtil {
14. /**
15. * summary:将字符串存储为文件 采用Base64解码
16. *
17. * @param fileStr
18. * @param outfile
19. *
20. */
21. public static void streamSaveAsFile(InputStream is, String outFileStr) {
22. FileOutputStream fos = null;
23. try {
24. File file = new File(outFileStr);
25. BASE64Decoder decoder = new BASE64Decoder();
26. fos = new FileOutputStream(file);
27. byte[] buffer = decoder.decodeBuffer(is);
28. fos.write(buffer, 0, buffer.length);
29. } catch (Exception e) {
30. e.printStackTrace();
31. throw new RuntimeException(e);
32. } finally {
33. try {
34. is.close();
35. fos.close();
36. } catch (Exception e2) {
37. e2.printStackTrace();
38. throw new RuntimeException(e2);
39. }
40. }
41. }
42.  
43. /**
44. *
45. *
46. * summary:将字符串存储为文件
47. *
48. * @param fileStr
49. * @param outfile
50. *
51. */
52. public static void stringSaveAsFile(String fileStr, String outFilePath) {
53. InputStream out = new ByteArrayInputStream(fileStr.getBytes());
54. FileStrUtil.streamSaveAsFile(out, outFilePath);
55. }
56.  
57. /**
58. * 将流转换成字符串 使用Base64加密
59. *
60. * @param in输入流
61. * @return
62. * @throws IOException
63. */
64. public static String streamToString(InputStream inputStream) throws IOException {
65. byte[] bt = toByteArray(inputStream);
66. inputStream.close();
67. String out = new sun.misc.BASE64Encoder().encodeBuffer(bt);
68. return out;
69. }
70.  
71. /**
72. * 将流转换成字符串
73. *
74. * @param in输入流
75. * @return
76. * @throws IOException
77. */
78. public static String fileToString(String filePath) throws IOException {
79. File file = new File(filePath);
80. FileInputStream is = new FileInputStream(file);
81. String fileStr = FileStrUtil.streamToString(is);
82. return fileStr;
83. }
84.  
85. /**
86. *
87. * summary:将流转化为字节数组
88. *
89. * @param inputStream
90. * @return
91. * @throws IOException
92. *
93. */
94. public static byte[] toByteArray(InputStream inputStream) throws IOException {
95. ByteArrayOutputStream out = new ByteArrayOutputStream();
96. byte[] buffer = new byte[1024 * 4];
97. byte[] result = null;
98. try {
99. int n = 0;
100. while ((n = inputStream.read(buffer)) != -1) {
101. out.write(buffer, 0, n);
102. }
103. result = out.toByteArray();
104. } catch (Exception e) {
105. e.printStackTrace();
106. throw new RuntimeException(e);
107. } finally {
108. out.close();
109. }
110. return result;
111. }
112.  
113. public static void main(String[] args) throws Exception {
114. String fromPath = "F://fileupload//aaa.docx";
115. String toPath = "C://Users//Desktop//aaaa.docx";
116. String fileStr = FileStrUtil.fileToString(fromPath);
117. FileStrUtil.stringSaveAsFile(fileStr, toPath);
118. }
119. }

文件\流\字符串互转

原文：https://www.cnblogs.com/dashazia/p/11477072.html