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)); X8*q[@$
} L:B&`,E
for(int i=0;i<nEndPos.length-1;i++) fNB*o={r|
{ k`TEA?RfQ
nEndPos = nStartPos[i+1]; yl3iU:+V
} t0?BU~f
nEndPos[nEndPos.length-1] = nFileLength; U15Hq*8Z
} yY,.GzIjCj
} Ye1P5+W(
[_H9l)
M(/%w"R
//启动子线程 B>~E6j7[Mp
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; S!g&&RDx
for(int i=0;i<nStartPos.length;i++) <y`yKXzBUV
{ ulVHsWg
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n}?kQOg0/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Ui1K66{
nStartPos,nEndPos,i); 'VF9j\a
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \8F$85g
fileSplitterFetch.start(); _G'.VSGH
} ]`:Fj|>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O`Z>Oon?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); X\YeO>C
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]`UJwq
nEndPos = " + nFileLength); Iem* 'r
// fileSplitterFetch[nPos.length-1].start(); N 4,w
u2U@Qrs2
o*dhks[
//等待子线程结束 fT'A{&h|U
//int count = 0; uYO?Rb&}
//是否结束while循环 7 H<_ wW
boolean breakWhile = false; cJH7zumM)
8SKDL[rN
w@oq.K
while(!bStop) VDQ&BmJE
{ -G*u2i_*
write_nPos(); <vbk@d
Utility.sleep(500); gw5CU)r4$
breakWhile = true; S9xC> |<
=#>P!
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for(int i=0;i<nStartPos.length;i++) lkl#AH
{ ,cbP yg
if(!fileSplitterFetch.bDownOver) 2poU\|H
{ _ k>j?j-
breakWhile = false; /?by4v73P
break; A 7TP1
} 9`vse>,-hg
} 2@A7i<p
if(breakWhile) L(X:=) !K0
break; s!UC{)g,
dn5T7a~
/+66y=`UJ
//count++; /=-E`%R}!
//if(count>4) 2U#OBvNU
// siteStop(); @c.QrKSaD
} ,sJ{2,]~
tc# rL
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System.err.println("文件下载结束！"); ~%GUc ~
} 5a_K|(~3I
catch(Exception e){e.printStackTrace ();} _39b8s{
} A}oR,$D-
cvc.-7IO
'MC)%N,
//获得文件长度 "w|GIjE+
public long getFileSize() ^TB%| yZ _
{ EcP"GO5
int nFileLength = -1; eQYW>z'%,
try{ 2>s:wABb /
URL url = new URL(siteInfoBean.getSSiteURL()); Ou,B3kuQ+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &Cdd
httpConnection.setRequestProperty("User-Agent","NetFox"); 67f#Z&r2k
Ho\z^w+T`
O0~[]3Y[=
int responseCode=httpConnection.getResponseCode(); =I*"vwc?
if(responseCode>=400) {zg}KiNDZd
{ ;,9|;)U?u
processErrorCode(responseCode); 0WYVt"|;}c
return -2; //-2 represent access is error 6idYz"P %
} NEK;'"~
WlG/7$
Zb}=?fcL;@
String sHeader; ~omX(kPzK
Yz{UP)TC
R=PjLH&)
for(int i=1;;i++) y+X%qTB
{ AMtFOXx%I
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "$m3xO
//Utility.log(in.readLine()); {L.0jAwB
sHeader=httpConnection.getHeaderFieldKey(i); HW{+THNj
if(sHeader!=null) mT\]
{ =(@J+Ou
if(sHeader.equals("Content-Length")) ukhI'alS,
{ )8P<ZtEU
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ee4oTU5Mb
break; q}+9$v
} VE{t]>*-u
} \t )Zk2
else 79S=n,O
break; ]Ub?Wo7F?
} w'cZ\<N[
} |%TH|?kB
catch(IOException e){e.printStackTrace ();} 2uqdx'^"
catch(Exception e){e.printStackTrace ();} H%sbf& gi
&o)j@5Y?
+/AW6
Utility.log(nFileLength); 80 p7+W2m
6``!DMDt/P
YZ'gd10T
return nFileLength; Soq 'B?>
} oSTGs@EK
@'~v~3 $S
@XB/9!
//保存下载信息（文件指针位置） B&<Z#C:I
private void write_nPos() 8<IOX
{ ?1?m4i
try{ T4w`I;&v
output = new DataOutputStream(new FileOutputStream(tmpFile)); LD#]"k
output.writeInt(nStartPos.length); {fk'g(E8([
for(int i=0;i<nStartPos.length;i++) l"O=xt`m{
{ ~hz]x^:
// output.writeLong(nPos); .}]5y4UQ.
output.writeLong(fileSplitterFetch.nStartPos); &K|CH? D
output.writeLong(fileSplitterFetch.nEndPos); Qs</.PO
} opdi5e)jK
output.close(); kjjO<x?&*
} IDwneFO
catch(IOException e){e.printStackTrace ();} dp-8,Seu
catch(Exception e){e.printStackTrace ();} i wK,XnIR
} +=;F vb
>_tn7Z0L
iQs(Dh=*
//读取保存的下载信息（文件指针位置） dt;R
private void read_nPos() H?^Poe(=(
{ )I`B+c:
try{ M(SH3~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @K2q*d
int nCount = input.readInt(); #@lLx?U
nStartPos = new long[nCount]; J`V7FlM
nEndPos = new long[nCount]; \$GlB+ iCx
for(int i=0;i<nStartPos.length;i++) vvdC.4O
{ W aks*^|
nStartPos = input.readLong(); :'a |cjq
nEndPos = input.readLong(); ~eE2!/%9
} z l@ <X0q
input.close(); y\V!OY@
} =][[TH
catch(IOException e){e.printStackTrace ();} f~8Xue,l"
catch(Exception e){e.printStackTrace ();} 1j3mTP
} v(]\o;/O
XeJx/'9o{
"J7=3$CA
private void processErrorCode(int nErrorCode) ZShRE"`
{ YzsHec
System.err.println("Error Code : " + nErrorCode); ~#7=gI&p@
} #t po@pJsE
;S2^f;q~$
B0nkHm.Sj
//停止文件下载 8T7[/"hi\
public void siteStop() dk-Y!RfNx
{ aJK8G,Vk
bStop = true; jh2D9h
for(int i=0;i<nStartPos.length;i++) U(.Ln@sq
fileSplitterFetch.splitterStop(); ]KLjQpd
lP\7=9rh^x
c9r, <TR9
} d5UdRX]*
} )>C,y`,
//负责部分文件的抓取 FdzsWm
**FileSplitterFetch.java G-9]z[\#
*/ mGwBbY+5n
package NetFox; 7WKb| /#;
_}{C?611c
K'Bq@6@C g
import java.io.*; h@@2vs2
import java.net.*; D3|y|Dr
d1vC-n N
{!Jw+LPv$$
public class FileSplitterFetch extends Thread { ,o*x\jrGw
Z2j M.[hq
[*]&U6\j
String sURL; //File URL 9<G-uF
long nStartPos; //File Snippet Start Position &0+;E-_
long nEndPos; //File Snippet End Position M&:[3u-
int nThreadID; //Thread's ID ;| )&aTdH
boolean bDownOver = false; //Downing is over nsuK{8}@
boolean bStop = false; //Stop identical M')f,5i&$
FileAccessI fileAccessI = null; //File Access interface rp{q.fy'U
K!0vvP2H
Y Dq5%N`
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException I?EtU/AD
{ Pur~Rz\\
this.sURL = sURL; <`+U B<K
this.nStartPos = nStart; /*B-y$WQk
this.nEndPos = nEnd; 3g0[(;
nThreadID = id; `og 3P:y
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Zu,rf9LMj
} 1#gveHm]-G
'K"V{
-1DQO|q#
public void run() {OXKXRCa
{ sy0|=E*;8"
while(nStartPos < nEndPos && !bStop) 3#!}W#xv
{ PsjSL8]
T/X[q7O~~4
T;-&3
try{ eR$qw#%c*
URL url = new URL(sURL); rB}Iwp8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j(AN]g:
httpConnection.setRequestProperty("User-Agent","NetFox"); I'Ui` :A
String sProperty = "bytes="+nStartPos+"-"; -iLp3m<ai
httpConnection.setRequestProperty("RANGE",sProperty); -hZlFAZi
Utility.log(sProperty); x_GD
A9`& Wnw?
2"cUBFc1I
InputStream input = httpConnection.getInputStream(); :*4b,P
//logResponseHead(httpConnection); om@GH0o+
Z@4BTA
,qz$6oxh\
byte[] b = new byte[1024]; ...|S]a
int nRead; w@ALl#z;}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) IlJ!jq
{ p2cwW/^V
nStartPos += fileAccessI.write(b,0,nRead); (&H-v'a}3
//if(nThreadID == 1) Y@)/iwq
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0hVw=KDO9:
} outAZy=R;
VEj-%"\
b1>zGC^|
Utility.log("Thread " + nThreadID + " is over!"); P|`pJYe
bDownOver = true; {ss^L
//nPos = fileAccessI.write (b,0,nRead); C@3a/<6m
} X0wvOs:
catch(Exception e){e.printStackTrace ();} <$7HX/P
} Lq: !?)I
} $Y& 8@/L
j?<>y/IR
OE[|1?3
//打印回应的头信息 1U[Q)(P
public void logResponseHead(HttpURLConnection con) <H03i"Z/S
{ xn|M]E1)
for(int i=1;;i++) "ld4v+o8l
{ 9ozN$:
String header=con.getHeaderFieldKey(i); F6^Xi"R[
if(header!=null) _=!Rl#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]06orBV
Utility.log(header+" : "+con.getHeaderField(header)); uJhB>/Og
else " iAwD8-
break; }22h)){n#Y
} L+VqTt
} W/e6O??O
~U"puEftbs
b/"&E'5-`\
public void splitterStop() "V|&s/9
{ StZ GKY[Q
bStop = true; mu`:@7+Yp
} NNDW)@p6z
}h{8i_R
CNP!v\D
} b`:n i
4k%y*L
LGuK@^
/* m ioNMDG
**FileAccess.java rnX D(
*//文件访问(定位，写) LkvR]^u0
package NetFox; &/wd_;d^A
import java.io.*; Dfz3\|LJ
/<zBjvr%%
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public class FileAccessI implements Serializable{ F%|F-6
PiQsVk
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 P?WS=w*O0
RandomAccessFile oSavedFile; .t53+<A
long nPos; -(~OzRfYi
%)'# d
y(81| c#
public FileAccessI() throws IOException `hpX97v
{ :xwyE(w
this("",0); 'LC-/_g
} 0o-.m
u_31Db<
oJ4OVfknD
public FileAccessI(String sName,long nPos) throws IOException +hiskV@v
{ L?h'^*F H}
oSavedFile = new RandomAccessFile(sName,"rw"); }(MI}o}
this.nPos = nPos; qK=uSLo\+
oSavedFile.seek(nPos); nev@ykP6
} o,(]w kF
cl,\N\
=o_Ua^mr
public synchronized int write(byte[] b,int nStart,int nLen) ;YGCsLT<xt
{ RV@'$`Q
int n = -1; ,76xa%k(U|
try{ L'A9TW2
oSavedFile.write(b,nStart,nLen); }Zuk}Og9+
n = nLen; {~*^jS']5
} Ij w{g%
catch(IOException e) @*>kOZ(3
{ }X|*+<
e.printStackTrace (); t,P_&0X
} mc FSWmq
YmwUl>@{
}.DE521u
return n; PPpq"c
} B r`a;yT
(D5sJ$&E@\
cVb&Jzd
} b aO^Z
UA0j#
.Tm m
/* (gHCu
**SiteInfoBean.java ^osXM`
*/ $:l>g)c
package NetFox; A.YXK%A%
E&z`BPd
&hnI0m=X
public class SiteInfoBean { @yImR+^.7
S&JsDPzSd
! )x2
private String sSiteURL; //Site's URL W[VbFsI&b
private String sFilePath; //Saved File's Path }w_r(g?\
private String sFileName; //Saved File's Name dilom#2l
private int nSplitter; //Count of Splited Downloading File <@448,9&
_/c1b>kcso
ko-,l6E
public SiteInfoBean() ; <NK
{//nSplitter的缺省值为5 '((pW
//default value of nSplitter is 5 {3LAK[C
this("","","",5); mxPzB#t4
} KHO@"+
R`HC EX)
y&&%%3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) d YliC
{ 5Q$.q&,
sSiteURL= sURL; iZ( U]
sFilePath = sPath; Gv(?u
sFileName = sName; P Y&(ObC
this.nSplitter = nSpiltter; iVSN>APe
UE\Z]t!
:w,#RcW
} /$=<"Y7&g
I%<LLkQ
4roqD;5|~|
public String getSSiteURL() eJ ;a}{ 4%
{ ;Pw\p^wz
return sSiteURL; $p;<1+!
} :3N&&]
p!Xn iY
QWQJSz5
public void setSSiteURL(String value) YZdV0-S
{ (~IoRhp^
sSiteURL = value; 7cQFH@SC
} % |^V)
pf8M0,AY
(ebC80M
public String getSFilePath() `EdZ
{ q).["fSV
return sFilePath; FGey%:p9$
} <y2HzBC
+5i~}Q!
q@=3`yQ
public void setSFilePath(String value) YwizA}a#
{ o|V`/sW{
sFilePath = value; % B^BN|r
} T B(K&3_D
dJ(<zz+;b
]8+ D
public String getSFileName() <L'6CBbP
{ $<da<}b
return sFileName; "$krK7Z
} )&{<gyS1
5<$8.a#
=9!|%j
public void setSFileName(String value) /g)(
{ csjCXT=Ve
sFileName = value; ,CxIA^
} 90Bn}@t=Q
IgyoBfj\d
5q,ZH6\ {
public int getNSplitter() s1>d)2lX
{ "&%Lhyt
return nSplitter; 7U1^=Y@t}
} H8!)zZ
5"9'=LV~
OK" fFv
public void setNSplitter(int nCount) ?1.WF}X'
{ 34F;mr"yp
nSplitter = nCount; j"r7M|Z+V
} !nDiAjj
} q|ZzGEj:OV
V\nj7Gr:sF
3EV?=R
/* 9<Ks2W.N
**Utility.java ~J![Nx/
*/ qYP;`L}o#
package NetFox; J{U 171
]o?r(1
f=hT o!i
public class Utility { VOSq%hB
z 4qEC
_;mA(j
public Utility() F*-+5nJ&@
{ b6NGhkr'\
Y[0mTL4IO
0[ZB^
} j8)rz
xnOd$]
//线程睡眠 aQ*?L l
public static void sleep(int nSecond) ?0tm{qP
{ B:96E&
try{ 7{lWg x
Thread.sleep(nSecond); : "^/?Sd
} B|K^:LUk9
catch(Exception e) MxDqp;
{ ]@!3os,CNF
e.printStackTrace (); l:+$Ks
} <Rfx`mn
} k&9[}a*
4^Og9}bm
//日志 Z+Cjg#+
public static void log(String sMsg) 4Opf[3]
{ pIHpjx
System.err.println(sMsg); ` >loleI
} cD t|v~
12@Ge]
k$|g)[RE
public static void log(int sMsg) Y|6gg
{ a+^,EY
System.err.println(sMsg); 9@8'*a{`m
} WP{U9YF2
} 9aBz%* xo
w>e+UW25Y
NG8F'=<
/* b}&.IJ&40j
**TestMethod.java uD\rmO{
*/ MZ?+I~@
package NetFox; TVF:z_M9
Vn65:" O
M(1cf(<+
public class TestMethod { i9Eh1A3Y
AC*SmQ\>!
PqMu2 e
public TestMethod() wf_ $#.;m
{ ///xx/weblogic60b2_win.exe ~^PNMZk
try{ i&q_h>ZTg
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,3 [FD9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); t?H sfN
SiteFileFetch fileFetch = new SiteFileFetch(bean); mNlbiB
fileFetch.start(); TBZhL
} 3hVuC1;"
catch(Exception e){e.printStackTrace ();} ?pWda<&
N/eus"O;
" {X0&
} @&x'.2[nv
LYr9a(
t&i4kS^y
public static void main(String[] args) |\xTcS|d
{ LrT? ]o
new TestMethod(); ZH<qidpR
} Qxfds`4V9i
} 55ft,a
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