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)); b~Q8&z2
} qZ=%ru
for(int i=0;i<nEndPos.length-1;i++) lk(.zYaaN
{ f#>ubmuI^
nEndPos = nStartPos[i+1]; 31-:xUIX
} w+_pq6\V
nEndPos[nEndPos.length-1] = nFileLength; ]/cVlpZ{f
} N3U.62
} Y(U+s\X
;;{!wA+"D
0D.qc8/V4.
//启动子线程 l!7O2Ai5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &i{>Li
for(int i=0;i<nStartPos.length;i++) 3*<?'O7I0
{ |%HTBF
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _*1{fvv0{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), I[g;p8jr
nStartPos,nEndPos,i); ,z@"pI b
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 552yzn1
fileSplitterFetch.start(); }]BH "
} +r<d z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I}hY @
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); V;-$k@$b.
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9\J6G8b>|I
nEndPos = " + nFileLength); @o/126(k
// fileSplitterFetch[nPos.length-1].start(); L0QF(:F5
[+8in\T i
r!C#PiT}I
//等待子线程结束 YYs/r
//int count = 0; W3~xjS"h
//是否结束while循环 xp68-&
boolean breakWhile = false; *;u'W|"/~
8p0ZIrD%
G\4*6iw:
while(!bStop) l2|[
{ T=~D>2C
write_nPos(); _Yqog/sG
Utility.sleep(500); SSH 1Ge5|
breakWhile = true; @4FG& >kQ
Ro:DAxi@L
#=V[vbTY
for(int i=0;i<nStartPos.length;i++) $!q(-+(
{ W+5<=jXFB
if(!fileSplitterFetch.bDownOver) nP5T*-~
{ }Kt1mmo:`
breakWhile = false; f8JWg9m
break; ):5M +
} </B<=tc
} duT'$}2@>
if(breakWhile) 0<4Nf]i
break; kWW$*d$
XhEJF !
vlSSw+r9
//count++; BSd\Sg4
//if(count>4) MUjfqxTT
// siteStop(); )&pcRFl
} ^(c.AYI
8H7=vk+
%Ix
System.err.println("文件下载结束！"); wUJ>?u9
} T-)lnrs^
catch(Exception e){e.printStackTrace ();} 1Ax{Y#<
} \:Vm7Zg
M4rK
q1_iV.G<
//获得文件长度 WH^^.^(i
public long getFileSize() P+2@,?9#
{ Mq,2S
int nFileLength = -1; 57~/QEdy
try{ 'OjsV$_
URL url = new URL(siteInfoBean.getSSiteURL()); )wdTs>W7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 79MF;>=tV
httpConnection.setRequestProperty("User-Agent","NetFox"); Gw@]w;ed
-:~"c@D
MIx,#]C&
int responseCode=httpConnection.getResponseCode(); K Ml>~r
if(responseCode>=400) 29tih{xx
{ 6(=>!+xpRr
processErrorCode(responseCode); -?}Z0e(w
return -2; //-2 represent access is error &cuDGo.
} 3-6Lbe9H
XFmTr@\M
40$- ]i
String sHeader; vp2s)W8W
Uz$.sa
=b_/_b$q
for(int i=1;;i++) QFX/x
{ (Rs052m1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); K}a3Bj,
//Utility.log(in.readLine()); (@nEe?
sHeader=httpConnection.getHeaderFieldKey(i); 5SQqE@g%
if(sHeader!=null) :JD*uu
{ _|f_%S8a_=
if(sHeader.equals("Content-Length")) {$P')>/
{ yO*HJpc
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #sHt3z)6I
break; $Si|;j$?
} ==]BrhZK
} &|Cd1z#?
else LE]mguvs
break; Sece#K2J|
} HY>zgf,0
} ?Jy/]j5fI
catch(IOException e){e.printStackTrace ();} 5e|yW0o
catch(Exception e){e.printStackTrace ();} W:S?_JM
zkb[u"
mO8E-D*3
Utility.log(nFileLength); 3!qp+i)?
`&w{-om\
U@:h';.
return nFileLength; Q4e+vBECkq
} 2Y1y;hCK
p{0NKyOvU
`JzP V/6
//保存下载信息（文件指针位置） >j6"\1E+Dz
private void write_nPos() #dhce0m
{ P+<4w
try{ pSKwXx
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]@wKm1%v
output.writeInt(nStartPos.length); c\DMeYrg
for(int i=0;i<nStartPos.length;i++) }-N4D"d4o
{ 5=hMTztf!!
// output.writeLong(nPos); n"g)hu^B
output.writeLong(fileSplitterFetch.nStartPos); 3](At%ss
output.writeLong(fileSplitterFetch.nEndPos); -I'Jm=q3]
} )l6(ss!J
output.close(); W'! I+nh
} 35 d:r:
catch(IOException e){e.printStackTrace ();} ArVW2gL
catch(Exception e){e.printStackTrace ();} uWDWf5@
} 4`zK`bRcK#
5iZx -M
hn[lhC
//读取保存的下载信息（文件指针位置） opfg %*
private void read_nPos() kps}i~Jb
{ ^`+Kjhht
try{ ?X^.2+]*&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i#KY'"P
int nCount = input.readInt(); *6/OLAkyF
nStartPos = new long[nCount]; x%`tWE|
nEndPos = new long[nCount]; 1<D^+FC4b,
for(int i=0;i<nStartPos.length;i++) 5H}d\=z
{ .Ge`)_e
nStartPos = input.readLong(); <pIel
nEndPos = input.readLong(); HyYol*
} /K :H2?J
input.close(); >41K>=K
} 1TlMB
catch(IOException e){e.printStackTrace ();} GV8`.3DBOF
catch(Exception e){e.printStackTrace ();} =<[M$"S7d6
} r8,'LZIz
XDyFe'1I
Oh;V%G
private void processErrorCode(int nErrorCode) TR'<D9kn
{ 5gKXe4}\/|
System.err.println("Error Code : " + nErrorCode); =z*SzG
} N~vK8j@
OICH:(t_
MmH(dp+
//停止文件下载 Y$0K}`{
public void siteStop() [oG Sy5bB
{ d$B+xW
bStop = true; %0q)PT\
for(int i=0;i<nStartPos.length;i++) }m93AL_y
fileSplitterFetch.splitterStop(); w~ O)DhC
*hlinQKs
[13NhF3.P
} D:0?u_[W
} +ux170Cd3
//负责部分文件的抓取 1 &-%<o
**FileSplitterFetch.java %@^9(xTE
*/ Pf#DBW*
package NetFox; q'KXn0IY#
,% *Jm
yC\!6pg
import java.io.*; C:ntr=3J
import java.net.*; so_^%) gdJ
&I7T?
'<1Q;3Ho
public class FileSplitterFetch extends Thread { 6F; |x
KvmXRf*z
HE@P<
String sURL; //File URL U"OA m}
long nStartPos; //File Snippet Start Position i?n#ge
long nEndPos; //File Snippet End Position 9)J)r\
int nThreadID; //Thread's ID C *]XQ1F4
boolean bDownOver = false; //Downing is over GzjC;+W
boolean bStop = false; //Stop identical !laOiH
FileAccessI fileAccessI = null; //File Access interface T)mh
* TByAa{
kb[+II
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,+!|~1
{ qF4=MQm\aE
this.sURL = sURL; TGzs|-
this.nStartPos = nStart; -?1ed|I8
this.nEndPos = nEnd; ofuQ`g1hb
nThreadID = id; UQO?hZ!y/.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +?^lnoX
} 6.6x$y3v
yX1OJg[s,
<4Ik]Uz^
public void run() u"-."_
{ ,B$e'KQ
while(nStartPos < nEndPos && !bStop) 1i}p?sU
{ pykRi#[UrX
V"5LNtf
`o6T)49
try{ q(Zu;ecBN
URL url = new URL(sURL); S#l)|c_~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -~_;9[uV
httpConnection.setRequestProperty("User-Agent","NetFox"); $: qrh66
String sProperty = "bytes="+nStartPos+"-"; O4T_p=Xc
httpConnection.setRequestProperty("RANGE",sProperty); N:UA+
Utility.log(sProperty); ^3ysY24Q
Kgb<uXk
C8$/z>tQ
InputStream input = httpConnection.getInputStream(); Q+Ya\1$6A
//logResponseHead(httpConnection); /JmWiBQIn
0RP{_1k
# N'_~:H
byte[] b = new byte[1024]; vjd;*ORB
int nRead; [t"#4[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )w0K2&)A
{ hSXZu?/
nStartPos += fileAccessI.write(b,0,nRead); UB7C,:"
//if(nThreadID == 1) Xagz(tm/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VV"1IR
} \= Wrh3
w C-x'
T^H`$;\
Utility.log("Thread " + nThreadID + " is over!"); *wV`7\@
bDownOver = true; L87=*_!B;
//nPos = fileAccessI.write (b,0,nRead); %i@Jw
} ~i=5NUE
catch(Exception e){e.printStackTrace ();} CM 8Ub%
} lQ|i Ws
} \<x{U3q5
{%QWv%|
.2/W.z2
//打印回应的头信息 <v$yXA
public void logResponseHead(HttpURLConnection con) :2-!bLo}&
{ GtkZ%<KF9
for(int i=1;;i++) ;xjw'%n,
{ =EUi|T4:
String header=con.getHeaderFieldKey(i); ?Bsc;:KF
if(header!=null) !N\i9w}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^\FOMGai
Utility.log(header+" : "+con.getHeaderField(header)); 3/*<i
else $-M'
break; kRB2J3Nt.
} %-3wR@
} y5N,~@$r
{ u1\M
MJG)fFl]O
public void splitterStop() nj7\vIR7
{ jT:kk
bStop = true; -](3iPy}
} WxS$yUu
b0[H{q-z{X
yA^+<uz}
} |=#uzp7*
eG%Q 3h
e*pYlm
/* RhI>Ak;-
**FileAccess.java ){"-J&@?
*//文件访问(定位，写) C%;J9(r
package NetFox; e18}`<tW-
import java.io.*; !f*t9 I9Q
Cm[^+.=I
P*{*^DN
public class FileAccessI implements Serializable{ v9l|MI15V
+t<'{KZ7;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Hb@PQcj
RandomAccessFile oSavedFile; UYsyVY`Fm|
long nPos; YE1X*'4
[+>cW0a
uOQl;}Lk5
public FileAccessI() throws IOException A9ru]|?
{ %<;PEQQ|C
this("",0); _2nNCu (
} mY!&*nYn|
1n EW'F
~\[\S!"
public FileAccessI(String sName,long nPos) throws IOException Dt]*M_
{ 2[Vs@X
oSavedFile = new RandomAccessFile(sName,"rw"); yn KgNi
this.nPos = nPos; T|ZJ$E0
oSavedFile.seek(nPos); o7t#yw3
} }XIUz|
^3w >:4m
|f<-lB[k
public synchronized int write(byte[] b,int nStart,int nLen) ~ A4_
{ H@BU/{
int n = -1; +BkmI\
try{ afj[HJbY
oSavedFile.write(b,nStart,nLen); t^(wbC
n = nLen; ^.(i!BG'
} ^y3snuLtE
catch(IOException e) +4m~D`fqt[
{ uz[5h0c
e.printStackTrace (); mNnt9F3Eq
} d9yfSZ
f>jAu;S
7Un5Y[FZo
return n; _J-3{a
} `T~~yM)q
rd!4u14
g;t>jgX
} 2j*o[kAE
!;COFR
z.]
/* V]0~BV
**SiteInfoBean.java 2^T`> ?{X
*/ ~6O<5@k
package NetFox; ,[|4{qli\
dEWI8Q]
I-o|~
public class SiteInfoBean { ylBjuD+
D+69U[P_A
8^av&u$
private String sSiteURL; //Site's URL 5_= HtM[v]
private String sFilePath; //Saved File's Path 6xAR:
private String sFileName; //Saved File's Name V~_aM@q1
private int nSplitter; //Count of Splited Downloading File Tq`rc"&7u
dMjAG7U
qo62!q
public SiteInfoBean() M_EXA _
{//nSplitter的缺省值为5 g=_@j`
//default value of nSplitter is 5 >Mc,c(CvU
this("","","",5); l[Rl:k!
} 0ntf%#2{
= ,^eQZR:
T{Y;-m
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) H3qM8_GUA
{ |%xgob
sSiteURL= sURL; ,]qTJ`J
sFilePath = sPath; Gs)2HR@>
sFileName = sName; `]3A#y)v
this.nSplitter = nSpiltter; mQy!*0y
Y> f 6
sQ>L3F;A`
} ~(/OB w
F)^:WWVc#
~Bs=[TNd[
public String getSSiteURL() lgaE2`0 [3
{ y{]iwO;
return sSiteURL; V [KFZSA
} j1U,X
O6Jn$'os1#
95^A !
public void setSSiteURL(String value) [ #1<W`95
{ uf<nVdC.
sSiteURL = value; N)b.$aC
} 2#?qey
|ZuS"'3_w
^i!6q9<{e
public String getSFilePath() K84VeAe
{ f hS4Gb_
return sFilePath; z6f N)kw
} szW85{<+
u AmDXqJ3
BT8L'qEj
public void setSFilePath(String value) YqSkz|o}m
{ -kI;yL
sFilePath = value; U";8zplU
} ,ThN/GkSC
;u "BCW
T0=%RID%=
public String getSFileName() \>@QJ
{ |SfmQ;
return sFileName; 9et%Hn.K'
} N5\]VCX
@XRN#_{
iR(jCD?) Y
public void setSFileName(String value) &q0s8'qA
{ 2J5RZg9jL
sFileName = value; WfF~\DlrD
} pNIu;1M5a
N);2 2-
N|53|H
public int getNSplitter() xvx+a0 A
{ />q?H)6
return nSplitter; C}>Pn{wY9
} P>s3Rh3:
F vt5vQ
;+-M+9"?O
public void setNSplitter(int nCount) :$J4T;/{
{ _bm8m4Lk
nSplitter = nCount; E|K~WO]>o
} DcL;7IT
} suP/I?4'@
u^Sa{Jk=
qe{:9
/* M!j: 2dT"
**Utility.java _cw~N p
*/ /3mt=1/~{B
package NetFox; aH!2zC\:T
py8)e7gX=
ZN `D!e6
public class Utility { 9C_Vb39::$
;#jE??E/:
{i09e1
public Utility() R%\K<#^\
{ K[~fpQGbV1
mv;;0xH
-{ M(1vV(=
} N& 683z
5U!yc7eBI/
//线程睡眠 n?=d)[]
public static void sleep(int nSecond) B{ptP4As-
{ VwKo)zH
try{ rMy(NAo_
Thread.sleep(nSecond); zs<2Ozv
} d=v{3*a_4,
catch(Exception e) =Mby;wQ?|
{ :,'yHVG\
e.printStackTrace (); [zv@}@$
} (m3 <)
} PZjK6]N\
`1fNB1c
//日志 ZS\~GQbG
public static void log(String sMsg) V^[B=|56
{ $pLJtQ
System.err.println(sMsg); z:7 i@m
} e!hy,O{Pw
o$%I{}9x
P/e6b .M
public static void log(int sMsg) LI`H,2Km
{ [')C]YQb=
System.err.println(sMsg); ,N`cH\
} e*?@6E
} )GC9%mF;
_a`J>~$
_d`)N
/* &u}]3E'-k
**TestMethod.java 94CHxv
*/ #i1z&b#@
package NetFox; yy(.|
a2!;$B%
|_GESpoHH
public class TestMethod { fp`k1Uq@
XJI ff$K
h:3^FV&#
public TestMethod() :)eU)r"s4
{ ///xx/weblogic60b2_win.exe n&N>$c,T27
try{ !x@3U^${
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); V[RsSZx =
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); OoqA`%
SiteFileFetch fileFetch = new SiteFileFetch(bean); u>y/<9]q8
fileFetch.start(); L55VS:'
} pX LXkF?
catch(Exception e){e.printStackTrace ();} @}+F4Xh,L
Ak'=/`+p
-D&d1`N4
} 76BA1x+G
RAUD8Z
~M?^T$5
public static void main(String[] args) QGoBugU
{ %%h0 H[5*
new TestMethod(); YM<F7tp4
} J7Y lmi
} P'<D0
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