http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); S,fCV~Cio?
} F1;lQA*7K.
for(int i=0;i<nEndPos.length-1;i++) 3T\l]? z
{ fjo{av~]y
nEndPos = nStartPos[i+1]; {C`GW}s{4
} :WGtR\tK
nEndPos[nEndPos.length-1] = nFileLength; 6SJ"Tni8
} pi(-A
} D8{D[fJ;
zxb/
n>,L=wV
//启动子线程 ;:S&F
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; e[u?_h
for(int i=0;i<nStartPos.length;i++) {",MCu_V
{ 2 gq$C"
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), GJi~y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 05Fz@31~
nStartPos,nEndPos,i); 148V2H)
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?[TfpAtQ`
fileSplitterFetch.start(); dCYCHHHF
} Zt -1h{7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), + Y.1)i}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _R|Ify#J
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", B@Co'DV[/]
nEndPos = " + nFileLength); @r(Z%j7
// fileSplitterFetch[nPos.length-1].start(); I-D^>\k+
:6J +%(f
i>L+gLW
//等待子线程结束 Uk*IpP`
//int count = 0; pY)5bSA
//是否结束while循环 M`,~ mU
boolean breakWhile = false; kB:Uu}(=N
S 6,4PP
a`9L,8Ve
while(!bStop) ))D:8l@
{ .D,p@4
write_nPos(); z2gk[zY&
Utility.sleep(500); Zv]x'3J#Y
breakWhile = true; yfQ5:X
z@|dzvjl Q
'z@0
for(int i=0;i<nStartPos.length;i++) Kr'f-{
{ c'6g*%2k
if(!fileSplitterFetch.bDownOver) 'XQ`g CF=
{ <oKGD50#
breakWhile = false; l}^3fQXI
break; Kemw^48ts
} GY3Wj
} }UJv[
if(breakWhile) nZ1zJpBmI
break; 5la>a}+!!h
.JX EK
l5%G'1w#,j
//count++; $w)~O<_U
//if(count>4) TlL^7f}
// siteStop(); C,V%B
} 1sE?YJP-
8*SDiZ
_8fr6tO+
System.err.println("文件下载结束！"); )C(>H93
} +:=(#Y
catch(Exception e){e.printStackTrace ();} (YBMsh
} %V&n*3
T#%/s?_>.
Sgim3):Z
//获得文件长度 v$~QCtc
public long getFileSize() L$'[5"ma ;
{ Tm^89I]L
int nFileLength = -1; y4Z&@,_{
try{ $CTSnlPq
URL url = new URL(siteInfoBean.getSSiteURL()); *b *G2f^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 682Z}"I0
httpConnection.setRequestProperty("User-Agent","NetFox"); n8=5-7UT
# ,uya2!)
%98' @$:0
int responseCode=httpConnection.getResponseCode(); &wd;EGGT!q
if(responseCode>=400) "q}FPJ^l_N
{ bawJ$_O_
processErrorCode(responseCode); i"zuil
return -2; //-2 represent access is error N#V.1<Y
} I jr\5FA[p
!g~1&Uw1
5Dp#u
String sHeader; =4uSFK_L
AIb2k
1XG!$4DW
for(int i=1;;i++) OJT1d-5p
{ YzosZ! L!<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); dpQG[vXe
//Utility.log(in.readLine()); { pu85'DV
sHeader=httpConnection.getHeaderFieldKey(i); ERwHLA
if(sHeader!=null) 7e7 M@8+4
{ =/<LSeLxH
if(sHeader.equals("Content-Length")) T@}|zDC#
{ .)1_Ew
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); hPq%Lc
break; g&dPd7
} IcP)FB4
} 4=uhh
else 64Lx-avf
break; R [H+qr
} }'r[m5T
} !-s!f&_
catch(IOException e){e.printStackTrace ();} ,1'4o3
catch(Exception e){e.printStackTrace ();} pZ`|iLNl-
=_j vk.
FYs)MO
Utility.log(nFileLength); umz;F
xw{-9k-~
A5,t+8`aci
return nFileLength; -(#I3h;I
} EM>}0V
%h1N3\y9i(
y(R? ,wa=]
//保存下载信息（文件指针位置） YV=QF J'
private void write_nPos() 2|\A7.
{ ld$i+6|
try{ Y_`-9'&
output = new DataOutputStream(new FileOutputStream(tmpFile)); <Q|d&vDVfV
output.writeInt(nStartPos.length); 5J8r8` t
for(int i=0;i<nStartPos.length;i++) '`'GK&)
{ =b;>?dP
// output.writeLong(nPos); \~P=U;l=pO
output.writeLong(fileSplitterFetch.nStartPos); Lb LiB*D#s
output.writeLong(fileSplitterFetch.nEndPos); sNun+xsf^
} Kn+S,1r
output.close(); "CiTa>x
} ]weoTn:
catch(IOException e){e.printStackTrace ();} NvM*h%ChM
catch(Exception e){e.printStackTrace ();} .ROznCe}
} "#mBcQ;QLV
S9HwIH\m
}68i[v9Njk
//读取保存的下载信息（文件指针位置） Nn>'^KZNG
private void read_nPos() =PGs{?+&O
{ f#ri'&}c :
try{ 0"~i^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "~TA SX_?
int nCount = input.readInt(); ?` SUQm
nStartPos = new long[nCount]; XMG]Wf^%\<
nEndPos = new long[nCount]; \uss Uv
for(int i=0;i<nStartPos.length;i++) 8H[:>;SI
{ S/;bU:
nStartPos = input.readLong(); R_=6GZH$G
nEndPos = input.readLong(); zB yqD$
} -i-?.:
input.close(); Z{'i F
} @F(mi1QO
catch(IOException e){e.printStackTrace ();} X.`~>`8
catch(Exception e){e.printStackTrace ();} !3T&4t
} fM^[7;]7e
#^+DL]*l
R$zH]
private void processErrorCode(int nErrorCode) 6q 2_WX
{ `6+"Z=:
System.err.println("Error Code : " + nErrorCode); #c^^=Z
} +iOKbc'
D7_*k%;@
VK@!lJu!
//停止文件下载 Q1@A2+ c
public void siteStop() 9mZ
{ |7x\m t
bStop = true; "`N-*;*W
for(int i=0;i<nStartPos.length;i++) \W,I?Kx$
fileSplitterFetch.splitterStop(); 36US5ef
^n0]dizB
/dnCwFXf
} ON+J>$[[
} NHlk|Y#6b
//负责部分文件的抓取 uslQ*7S[^
**FileSplitterFetch.java +}jJ&Z9)
*/ XrZ*1V
package NetFox; V)}rEX
v%Wx4v@%SE
,AT[@
import java.io.*; F-6c_!
import java.net.*; \TU3rk&X
y(K" -?
~i 7^P9
public class FileSplitterFetch extends Thread { 0Won9P
QY== GfHt
Y3Q9=u*5
String sURL; //File URL 4j)tfhwd8
long nStartPos; //File Snippet Start Position aMTu-hA
long nEndPos; //File Snippet End Position qx%}knB
int nThreadID; //Thread's ID \6\<~UX^
boolean bDownOver = false; //Downing is over qP<Lr)nUH
boolean bStop = false; //Stop identical v0L\0&+
FileAccessI fileAccessI = null; //File Access interface &c1A*Pl/:G
dO%W+K
7 [0L9\xm
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException sJNFFOz
{ $ MC)}l
this.sURL = sURL; GgKEP,O
this.nStartPos = nStart; )p*}e8L
this.nEndPos = nEnd; .1LCXW=
nThreadID = id; $8BPlqBIZ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 i~r l o^
} z;y:9l
3po:xMY
|fo0
public void run() 5eWwgA
{ }l=xiAF
while(nStartPos < nEndPos && !bStop) OrK&RC
{ 0]4(:(B
bJD;>"*
ge8/``=
try{ 63A}TBC
URL url = new URL(sURL); K<>sOWZ'S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @e{^`\l=<
httpConnection.setRequestProperty("User-Agent","NetFox"); D+>1]ij
String sProperty = "bytes="+nStartPos+"-"; &iV{:)L
httpConnection.setRequestProperty("RANGE",sProperty); c%qv9
Utility.log(sProperty); N;[>,0&z
1x,tu}<u^
+sJrllrE(
InputStream input = httpConnection.getInputStream(); zen*PeIrA^
//logResponseHead(httpConnection); [ Fz`D/
n?c]M
&zo|Lfe
byte[] b = new byte[1024]; @/1w4'M
int nRead; iJ~Vl"|m
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) D:K4H+ch
{ nWHa.H#
nStartPos += fileAccessI.write(b,0,nRead); =lpQnj"
//if(nThreadID == 1) @K!&qw
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !Ta>U^7
} 1</kTm/Qa
[ I/<_AT#
QMZ)-ty"
Utility.log("Thread " + nThreadID + " is over!"); v~Y^r2
bDownOver = true; +[tP_%/r'^
//nPos = fileAccessI.write (b,0,nRead); uyY|v$FM
} &@3H%DP}Ql
catch(Exception e){e.printStackTrace ();} |p-t%xDdr
} C/-63O_
} [VWUqlNt>
uDZT_c'Y
y TDNNK
//打印回应的头信息 Kde9 $
public void logResponseHead(HttpURLConnection con) b4pm_Um
{ &ZQJ>#~j^
for(int i=1;;i++) ~_!F01s
{ L/z),#
String header=con.getHeaderFieldKey(i); p"U,G -_
if(header!=null) yR\btx|e5~
//responseHeaders.put(header,httpConnection.getHeaderField(header)); zi3\63D3eO
Utility.log(header+" : "+con.getHeaderField(header)); pf7it5
else [#sz WNfU
break; *H|M;G
} `F>O;>i''
} T|6a("RL
&sd}ulEg`
G}G#i`6o
public void splitterStop() j.@\3'
{ f@c`8L@g
bStop = true; ~b2wBs)r
} ,zTy?OQ
#KiRfx4G
}3L@J8:D"
} A\.GV1
L{`JRu
E)fglYWs2
/* s91JBP|B7
**FileAccess.java UMcgdJB
*//文件访问(定位，写) z.I9wQ]X[
package NetFox; }:~x7|~s:
import java.io.*; L:'J Bhg
5hy""i
+PuPO9jKO@
public class FileAccessI implements Serializable{ W}]%X4<#rN
NSDv;|f
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _zwUE
RandomAccessFile oSavedFile; 'uxX5k/D@t
long nPos; s]JF0584
_> *jH'
!U~WK$BP
public FileAccessI() throws IOException $ <#KA3o\
{ 8M`#pN^
this("",0); HF.^ysI
} 82DmG@"s2
KkE9KwZ]W
I}vmU^Y>
public FileAccessI(String sName,long nPos) throws IOException ^!by3Elqqk
{ +@/"%9w
oSavedFile = new RandomAccessFile(sName,"rw"); S9",d~EM
this.nPos = nPos; 8zR~d%pK
oSavedFile.seek(nPos); k'5?M
} ksN+?E4w
}I2@%tt?
fOMW"myQ
public synchronized int write(byte[] b,int nStart,int nLen) 9b*nLyYVz
{ a)'5Nw9*
int n = -1; %&Q$dzgb_
try{ aWY gR
oSavedFile.write(b,nStart,nLen); !!? Mw
n = nLen; BFOq8}fX2
} jE/AA!DC#
catch(IOException e) }-sdov<<
{ +qwjbA+
e.printStackTrace (); L-k@-)98
} ynhmMy%
V:c;-)(
"PpN0Rr
return n; mA=i)Ga
} Oal3rb
Q{lpKe0
OUNd@o
} ^cz(}N 6&
t>$kWd{9e;
[a wjio
/* fu]s/'8B
**SiteInfoBean.java LMAE)]N
*/ sU{NHC)5
package NetFox; vsl]92xI
c>)Yt^q&K
d>t<_}
public class SiteInfoBean { I]EbodAyZ,
07^iP>?
ptZ <ow&
private String sSiteURL; //Site's URL ?TKRjgW`@_
private String sFilePath; //Saved File's Path E`uY1B[c
private String sFileName; //Saved File's Name SF<c0bR9
private int nSplitter; //Count of Splited Downloading File 4Q6mo/=H
d*%`!G
9uA>N
public SiteInfoBean() ]h %Wiw
{//nSplitter的缺省值为5 u2?|Ue@[
//default value of nSplitter is 5 0p!>JQ]m
this("","","",5); n4#;k=mA
} n$ou- Q
57&b:0`p
S-|)QGxV6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,^. 88<
{ k+ty>bP=
sSiteURL= sURL; D,k"PaLP
sFilePath = sPath; Y/ .Z.FD`
sFileName = sName; Us0EG\Y
this.nSplitter = nSpiltter; Z Z:}AQ
PU^l.
n74V|b6W
} ='Y!+
zp%Cr.)$
TO?R({yx*
public String getSSiteURL() 7OJ'){R$
{ n+A?"`6*#
return sSiteURL; &RnTzqv
} n' q4
S9~+c
&b%zQ4%d-`
public void setSSiteURL(String value) LH8 fBhw
{ )]H-BIuGm
sSiteURL = value; t? yz
} G#u6Am)T
e3nYbWBy]
P>NF.BCq
public String getSFilePath() g9Xu@N;bL
{ uJC~LC N
return sFilePath; c_'OPJ
} \Ani}qQ%|
|m^k_d!d
G2Qlt@.T
public void setSFilePath(String value) |n,<1QY
{ iA'lon
sFilePath = value; y+c|vdW%
} )\J+Kiy)
1Y7Eajt-5
V4'YWdTi
public String getSFileName() &)AVzN+*h
{ j)/nKh4O
return sFileName; /7|V+6jV
} ; Q3n
'kL#]
$JMXV
public void setSFileName(String value) %&w3;d;c
{ Wp!%-vzy&
sFileName = value; XH}\15X
} |ZRagn30
lFV N07hG
6i.-6></
public int getNSplitter() oPXkYW
{ V9{]OV%
return nSplitter; b`~p.c%(
} ymx>i~>7J
DVB{2~7 4
4{rZppm
public void setNSplitter(int nCount) S||}nJ0
{ ;>?rP88t
nSplitter = nCount; 7BK0}sxO
} s/q7.y7n{
} p~BRh
,!Z*5
DRp~jW(\y
/* 1DE<rKI
**Utility.java lyy W
*/ QgU8s'e
package NetFox; \eT5flC
bzuEfFaL
r^3acXl
public class Utility { -EkWs/'h
'B 43_
CF&6J$ZBgJ
public Utility() \Zqng
{ naYrpK,.
>0ph9$
;CmS ~K:
} s;S?;(QI
XWS%zLaK
//线程睡眠 j/r]wd"aUS
public static void sleep(int nSecond) r? NznNVU
{ =|3ek
try{ T92UeG
Thread.sleep(nSecond); X(]WVCu
} _wkVwPr
catch(Exception e) |)b6>.^
{ H%UL%l$
e.printStackTrace (); zr+zhpp
} LcB]Xdsa(
} 5_I->-<
;#xmQi'`
//日志 4'`{H@]tb
public static void log(String sMsg) \N!AXD
{ [E!oQVY
System.err.println(sMsg); aE&,]'6
} m#PY,y
Y^8C)p9r
K?B{rE Lp
public static void log(int sMsg) b\vKJ2
{ @z4*.S&tz
System.err.println(sMsg); 544X1Ww2
} Pe3@d|-,MU
} XC0bI,Fu,
'IZI:V"
B$ajK`x&I
/* .aAL]-Rj
**TestMethod.java u frW\X
*/ %k-3?%&8
package NetFox; ein4^o<f.
Kwefs;<E?
\Xm,OE_v"
public class TestMethod { WQ[_hg|k
ewa wL"
lef2X1w}!
public TestMethod() -+ SF
{ ///xx/weblogic60b2_win.exe - }7e:!.
try{ ej4W{IN~:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); y.#")IAF
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); dv8>[#
SiteFileFetch fileFetch = new SiteFileFetch(bean); U3T#6Rptl
fileFetch.start(); *.sVr7=j
} v0-cd
catch(Exception e){e.printStackTrace ();} %W%9j#!aN
10<x.8fSP
|Y$uqRdV
} *)ardZV${
1crnmJ!C
s}UjGFP
public static void main(String[] args) UDL!43K
{ +Z7th7W/,
new TestMethod(); pk?w\A}
} _/uFsYC
} K/tRe/t}
点击下载更多相关资料