http断点续传简单实现（java)

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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)); \%<M[r=
} F! =l r
for(int i=0;i<nEndPos.length-1;i++) +W4}&S
{ OZ\6qMH3e
nEndPos = nStartPos[i+1]; ",,#q
} Mj;V.Y
nEndPos[nEndPos.length-1] = nFileLength; m*m),mZ"
} -,bnj^L
} 811>dVq3/
#gbB// <
d?7?tL2
//启动子线程 `XxnQng
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; @v2<T1UC
for(int i=0;i<nStartPos.length;i++) EHUx~Q
{ { b$"SIg1E
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {R_>KE1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), TAXsL&Tz>
nStartPos,nEndPos,i); 6+$2rS$1V
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -;9 }P
fileSplitterFetch.start(); J+/}m}bx
} *73gp
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c'2/C5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ujV{AF`JfB
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]s=|+tz\V
nEndPos = " + nFileLength); ;TL.QN/l
// fileSplitterFetch[nPos.length-1].start(); `<9>X9.+
LGt>=|=bj
4]r_K2.cc
//等待子线程结束 H9)@q3<
//int count = 0; PCl5,]B}
//是否结束while循环 _)45G"M
boolean breakWhile = false; O|H:
u ON(LavB
r,;ca6>5H
while(!bStop) Et3]n$
{ /x49!8
write_nPos(); (H_dZL
Utility.sleep(500); '?C6P5fm
breakWhile = true; uo`R
yX!u&
h]<S0/
for(int i=0;i<nStartPos.length;i++) brA#p>4]Wf
{ g,d_
if(!fileSplitterFetch.bDownOver) u=0O3-\h
{ &D3]O9a0;
breakWhile = false; &3SS.&g4W
break; IHTimT?
} * BM|luYL
} vX:}tir[
if(breakWhile) h /
break; _r-LX"
w*`:v$
:9QU\{2
//count++; g`pq*D
//if(count>4) |mtW)
// siteStop(); ZxvH1qx8
} h:fiUCw
4AJ]qu
JX0M3|I=
System.err.println("文件下载结束！"); dWd%>9}
} S1$^ _S =
catch(Exception e){e.printStackTrace ();} +@ChZ
} %"`p&aE:
jt}Re,
xJ3C^b%H
//获得文件长度 FQ>$Ps*a[
public long getFileSize() ]ogifnwv
{ t/[lA=0 )2
int nFileLength = -1; yv-R<c!'
try{ ebze_:
URL url = new URL(siteInfoBean.getSSiteURL()); +iC:/CJL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }T[@G6#
httpConnection.setRequestProperty("User-Agent","NetFox"); kx&JY9(&#
5qrD~D'
b^HDN(v
int responseCode=httpConnection.getResponseCode(); \=0;EI-j
if(responseCode>=400) ]1++$Ej
{ )|*Qs${tF
processErrorCode(responseCode); o^epXIrIPi
return -2; //-2 represent access is error Nk9=A4=|
} *5Zow3
:[<Y#EX.
PtkMzhX
String sHeader; \d"\7SA
CmB_g?K
O_;BZzT
for(int i=1;;i++) Bj7*2}
{ +,spC`M6h
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); N1'"7eg/
//Utility.log(in.readLine()); ^ =C>
sHeader=httpConnection.getHeaderFieldKey(i); #czInXTTx
if(sHeader!=null) jzf~n~
{ !l*A3qA
if(sHeader.equals("Content-Length")) ,g?ny<#o
{ p8,=K<
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); k1,k 9BK
break; 30HUY?'K
} A"S"La%"
} ]\yB,
else >n,_Aj c
break; Q+1ot,R
} 8fqabR
} wKpGJ& {
catch(IOException e){e.printStackTrace ();} .OJGo<#$f
catch(Exception e){e.printStackTrace ();} 0se%|Z|8
F/2cQ.u2
tz]0F5
Utility.log(nFileLength); r $S9/
2xN7lfu1RB
"[ LUv5
return nFileLength; g/C 7wc
} |&@q$d
%uo8z~+
j#f/M3
//保存下载信息（文件指针位置） OmuE l>
private void write_nPos() :Pq&l.
{ "1s ]74
try{ $2Wk#F2c=
output = new DataOutputStream(new FileOutputStream(tmpFile)); =\]gL%N-|
output.writeInt(nStartPos.length); w5z]=dN
for(int i=0;i<nStartPos.length;i++) `)a|Q
{ 4&NB xe
// output.writeLong(nPos); TzC(YWt
output.writeLong(fileSplitterFetch.nStartPos); ,P<I<QYu
output.writeLong(fileSplitterFetch.nEndPos); _ %mm
} !po,Z&
output.close(); Mh`^-*c?
} 7ZI{A*^vB
catch(IOException e){e.printStackTrace ();} u8 k^\Do
catch(Exception e){e.printStackTrace ();} I0Do%
} p+P@I7V
n`=S&oKH
=-!jm? st*
//读取保存的下载信息（文件指针位置） k?h{6Qd
private void read_nPos() Mzg3i*
{ \zJ^XpC
try{ ^:?z7m
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?e-rwaW
int nCount = input.readInt(); SsX$l<t*
nStartPos = new long[nCount]; (&m1*
nEndPos = new long[nCount]; 5tv*uz|fv
for(int i=0;i<nStartPos.length;i++) L\ysy2E0
{ s-*N_Dv
nStartPos = input.readLong(); _dd_Z40R
nEndPos = input.readLong(); KdR\a&[MA
} %enJ[a%Qg
input.close(); ` .`:~_OE
} ~6#mVP5sU)
catch(IOException e){e.printStackTrace ();} ZS:[ZehF
catch(Exception e){e.printStackTrace ();} S*}GW-)oA
} 9>+>s ?IgK
nxN("$'cq
zpT{!V
private void processErrorCode(int nErrorCode) |g7)A?2J~
{ 9I 6^-m@:
System.err.println("Error Code : " + nErrorCode); Mxz X@GBX
} 4oF,;o+v\4
36'J9h\
rKPsv*w
//停止文件下载 2;]tItd1
public void siteStop() lJa-O
{ _`Kh8G {e
bStop = true; 'NWvQR<X
for(int i=0;i<nStartPos.length;i++) BfCib]V9C
fileSplitterFetch.splitterStop(); =SJ[)|
|QzJHP @
,=!s;+lu{
} ZHen:
} N+SA$wG
//负责部分文件的抓取 Q9y|1Wg1W
**FileSplitterFetch.java iP7KM*ks
*/ e7G>'K
package NetFox; /_fZ2$/
h<m>S,@g
b<fN,U<k
import java.io.*; Ct/6<
import java.net.*; @W+8z#xr'
,,XHw;{
RW>F %P
public class FileSplitterFetch extends Thread { m$Tt y[0
/XRgsF
ivdPF dJ
String sURL; //File URL }J5iY0
long nStartPos; //File Snippet Start Position /x-tl)(s=
long nEndPos; //File Snippet End Position ICoZ<;p
int nThreadID; //Thread's ID L%9yFg%u
boolean bDownOver = false; //Downing is over avS9"e
boolean bStop = false; //Stop identical 6w<p1qhW
FileAccessI fileAccessI = null; //File Access interface UL7%6v{'*
~R|fdD/%
Cyv_(Oh?dv
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException p*P0<01Z
{ 7;}TNK\+v
this.sURL = sURL; UIQ=b;J9
this.nStartPos = nStart; *|+ ~V/#
this.nEndPos = nEnd; n=fR%<v
nThreadID = id; }xrrHp
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <.7W:s,f=
} RkdAzv!Y7
# 9f 4{=\
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public void run() `Geq,
{ 0@f7`D
while(nStartPos < nEndPos && !bStop) ,Ur~DXY
{ B7ys`eiB5C
'\m\$ {
GLl@ 6S>v
try{ 7f=9(Zj
URL url = new URL(sURL); -JF|770i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Qzk/oHs
httpConnection.setRequestProperty("User-Agent","NetFox"); A[d'*n[
String sProperty = "bytes="+nStartPos+"-"; X>jwjRK $
httpConnection.setRequestProperty("RANGE",sProperty); q33!X!br
Utility.log(sProperty); r52,f%nlm
uP ?gGo
\;tKss!|
InputStream input = httpConnection.getInputStream(); qpc2;3*7
//logResponseHead(httpConnection); OaxE3bDT
tX*L_
Df/f&;`
byte[] b = new byte[1024]; Q^V`%+
int nRead; r3{o_w
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) w_J`29uc
{ "=!QSb
nStartPos += fileAccessI.write(b,0,nRead); {&(bKQ
//if(nThreadID == 1) ]O&A:Us
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +ACV,GG
} ;v+CQx
e;}5~dSi
>Q\H1|?
Utility.log("Thread " + nThreadID + " is over!"); ?Ve5}N
bDownOver = true; J=]w$e ?.P
//nPos = fileAccessI.write (b,0,nRead); 8CSvg{B
} !c`Q?aGV)
catch(Exception e){e.printStackTrace ();} zsRN\U
} R}+/jh2O|
} XKU=VOY
lR^dT4
z8"=W,2
//打印回应的头信息 |V~P6o(/
public void logResponseHead(HttpURLConnection con) *&2#;mf3
{ GrQAho
for(int i=1;;i++) <db/. A3
{ t_VHw'~"
String header=con.getHeaderFieldKey(i); E[Io8|QA
if(header!=null) %J%gXk}]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :~)Q]G1Nj
Utility.log(header+" : "+con.getHeaderField(header)); $v oyXi`*
else RBgkC+2
break; izWl5}+'B
} 3S2'JOTY
} |]\bgh
+[}]a3)
/~tfP
public void splitterStop() zB]T5]
{ ;<X3AhF
bStop = true; '}YXpB
} K :q-[\G
m<f{7]fi5
?HcA&
} E:E&Wv?r
# nYGKZ
YV940A-n
/* qiF~I0_0
**FileAccess.java t@JPnA7~
*//文件访问(定位，写) H62*8y8
package NetFox; X9gC2iSs]
import java.io.*; Z "=(uwM
O.}gG6u5
z|?R=;,u`
public class FileAccessI implements Serializable{ y?@Y\ b
aC$g(>xFt
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 B+DRe 8
RandomAccessFile oSavedFile; \j;uN#)28
long nPos; cnPXvD^kY
(MIw$)#^
R39R$\
public FileAccessI() throws IOException 5)oIPHXw
{ B:r-')!0$#
this("",0); "=n8PNV/ c
} ;Gs**BB&
.}<B*e=y
9iy|=
public FileAccessI(String sName,long nPos) throws IOException @ :4Kk 4g1
{ pNJM]-D]m~
oSavedFile = new RandomAccessFile(sName,"rw"); 9cmJD5OO
this.nPos = nPos; +?:V\niQI
oSavedFile.seek(nPos); \ +xIH
} l>(G3lIw
2*L/c-
fBOPd=
public synchronized int write(byte[] b,int nStart,int nLen) ge oN4
{ _Usg`ax-
int n = -1; *&0Hz{|
try{ `j<tI6[e
oSavedFile.write(b,nStart,nLen); ?^vZ{B)&0E
n = nLen; f,a %@WT
} Lb{D5k*XU
catch(IOException e) y&Hh8|'mC
{ OA=;9AcZ
e.printStackTrace (); ?.4l1X6Ba
} ibc/x v2
Xh/av[Q
~=mM/@HD
return n; feW9>f;
} E\S&} K,s
bN&da [K
r?I(me,
} nu<!/O
tp^'W7E
U}0/V c26
/* a&hM:n4P
**SiteInfoBean.java z.^ )r
*/ @#tSx
package NetFox; T_Y}1n|7[
{@$3bQ
6<Wr 8u,
public class SiteInfoBean { j[`?`RyU
7$=@q|$
+3>4 ?,^g
private String sSiteURL; //Site's URL ;LE @Ezx
private String sFilePath; //Saved File's Path jf/9]`Hf
private String sFileName; //Saved File's Name k#) .E X
private int nSplitter; //Count of Splited Downloading File &zcjU+n
Sh6Cw4 R
Vgn1I(Gj4
public SiteInfoBean() 1W[(+TZ&s
{//nSplitter的缺省值为5 g:M7/- "
//default value of nSplitter is 5 b]#d04]
this("","","",5); !S-U8KI|
} [ d7]&i}*|
<pUou
<;e#"(7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) XE*bRTEw
{ *^Y0}?]qT
sSiteURL= sURL; 3raA^d3!?
sFilePath = sPath; ^b %8_?2m
sFileName = sName; J"%}t\Q
this.nSplitter = nSpiltter; T_[\(K`w!
oLMi vy4
CWQ2iu<_0
} m5aaY
?\M6P?tpo&
zpqNmxmF
public String getSSiteURL() x 4</\o
{ mm-UQ\h
return sSiteURL; l|em E ^
} a[g|APZz
6ya87H'e@
1T,PC?vr{
public void setSSiteURL(String value) E_1I|$
{ C}'="g^=sl
sSiteURL = value; S)@vl^3ec
} ;S`-9}6
'\B"g@if
h)^A3;2F
public String getSFilePath() !o':\hex6
{ E2H<{Q
return sFilePath; O:tX0<6
} bXwoJ2
ZCFf@2&z8
xevP2pYG:
public void setSFilePath(String value) E0^%|Mh]b
{ 0uO=wOIhH
sFilePath = value; u7P+^A97L_
} RLOQ>vYY
0(/D|
etMh=/NFV
public String getSFileName() Guw|00w,Q$
{ 8{SU?MHQLE
return sFileName; Ij}F<ZgZG
} xTFrrmxOf
~uR6z//%
A a} o*
public void setSFileName(String value) @@3,+7%1
{ Vy^yV|`v
sFileName = value; FEZ"\|I|
} h`h>H X
:@%-f:iDj
(S)E|;f%C
public int getNSplitter() W({TC
{ j-`X_8W
return nSplitter; ~J>gVg%66
} =Cy>$/H64
tK|9qs<%
1m<?Q&|m$
public void setNSplitter(int nCount) !H|82:`t+
{ Ryba[Fz4Di
nSplitter = nCount; 3E!<p
} h>Uid &:?
} vo6[2.HS
.d~]e2x
^Z>B/aJq
/* xPDA475Cw3
**Utility.java F\=Rm
*/ Ep\
package NetFox; fHe0W
FL#g9U>
Uy59zB2|=
public class Utility { r3H}*Wpf
^/C$L8#
1 73<x){
public Utility() ,d>X/kd|o
{ ?7kV+{.
of'ZNQ/
!q$&JZY
} jxnQG A
En,)}yI
//线程睡眠 }xf='lE
public static void sleep(int nSecond) nRXSW&V"m
{ kUg+I_j6*
try{ UGmuX:@y76
Thread.sleep(nSecond); :qAc= IC%
} =l8!VJa
catch(Exception e) 833%H`jQc
{ uojh%@.4
e.printStackTrace (); ! nCjA\$
} _[TH@fO6:
} C^/ -lc
d2A wvP
//日志 I>H;o{X#
public static void log(String sMsg) %|*nmIPq(
{ Foe>}6~{?
System.err.println(sMsg); dgco*TIGO
} v;fJM5PA
s~Lfi.
:J Gl>V
public static void log(int sMsg) 'n^2|"$sH
{ ntj`+7mw
System.err.println(sMsg); =|E 09
} \m=-8KpU
} A \MfF
8 )mjy!,
-7I1Lh#M
/* #ox9&
**TestMethod.java q}<.x8\
*/ 1iNsX\M
package NetFox; oNuPP5d[]
\6SMn6a4
PG6[lHmi
public class TestMethod { X(GmiH /E
C#Hcv*D
~5r=FF6
public TestMethod() Ig1lol:;
{ ///xx/weblogic60b2_win.exe <H5n>3#pH
try{ aFRTNu/r
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9Qzjqq:"Li
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ='dLsh4P2N
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1 [Sv
fileFetch.start(); YVB% kKv{
} (px*R~}
catch(Exception e){e.printStackTrace ();} X~v4"|a
5c:'>
I!fB1aq-
} cq*p9c
_m9~*
`E3:;|
public static void main(String[] args) 2Vp>"
{ X,RT<GNNb
new TestMethod(); (TEo_BW|+
} 87^:<\pp
} R9tckRG#
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