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)); Q(WfWifu-|
} 'mv|6Y
for(int i=0;i<nEndPos.length-1;i++) _x-2tnIxXv
{ D41.$t[
nEndPos = nStartPos[i+1]; }WR@%)7ay
} #p{8
nEndPos[nEndPos.length-1] = nFileLength; 1@-l@ P
} ?iaO+G&|
} `^g-2~
9e;{o,r@
O|v8.3[cT
//启动子线程 Nog{w
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; JBV 06T_4o
for(int i=0;i<nStartPos.length;i++) G]-\$>5R
{ # b3 14
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ieOw&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), FIJ]`
nStartPos,nEndPos,i); (h&=Na~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ) [)1
fileSplitterFetch.start(); Qc Xw -
} R{B5{~m>W@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U~|)=+%O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :p1_ij]ND
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Oxi^&f||`
nEndPos = " + nFileLength); AAi4} 8+\
// fileSplitterFetch[nPos.length-1].start(); gxDyCL$h3
1"l48NLL|
b^~4k; <
//等待子线程结束 p%Ns f[1>
//int count = 0; So NgDFD
//是否结束while循环 wG 5H^>6u>
boolean breakWhile = false; [MAvU?;
E0A[{UA
-t*P=V|@
while(!bStop) q)"yP\
{ M VE:JNm
write_nPos(); #E/|WT
Utility.sleep(500); 4SkCV
breakWhile = true; 0sq?>$~Kc*
?;rRR48T9E
9:!V":8q
for(int i=0;i<nStartPos.length;i++) >(gbUW
{ %zjyZ{=
if(!fileSplitterFetch.bDownOver) t4zKI~cO
{ PTF|"^k+
breakWhile = false; {o%OG/!1
break; R|\kk?,u
} 9KL)5_6 M
} tac_MtW?
if(breakWhile) o^d
break; m7cG]a~a
fo;^Jg.
q' t"
//count++; @Bsvk9}
//if(count>4) J32"Ytdo<
// siteStop(); RHI?_gf&
} e=i9l
dY?>:ce
1mv8[^pF
System.err.println("文件下载结束！"); xn<x/e
} w\>@>*E>
catch(Exception e){e.printStackTrace ();} T#YJ5Xw
} F@xKL;'N74
dsZ-|C
KctbNMU]k
//获得文件长度 [TmZ\t!5$
public long getFileSize() `$] ZT>&
{ \uOR1z
int nFileLength = -1; zrA=?[
try{ `9DW}
URL url = new URL(siteInfoBean.getSSiteURL()); e$-Y>Dd
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "2 qivJ
httpConnection.setRequestProperty("User-Agent","NetFox"); F,xFeq$/{
239gpf]}
d?[8VfAnh
int responseCode=httpConnection.getResponseCode(); GS,}]c=
if(responseCode>=400) Ye\&_w"
{ [58qC:
processErrorCode(responseCode); qD(dAU
return -2; //-2 represent access is error Mgux(5`;
} fp$U%uj
2()/l9.O'
Y-v6M3$
String sHeader; ^B'N\[
$btk48a7
P\2x9T
for(int i=1;;i++) N}\3UHtO
{ U1pwk[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?fvK<0S`
//Utility.log(in.readLine()); 810uxw{\
sHeader=httpConnection.getHeaderFieldKey(i); Nf9$q| %!
if(sHeader!=null) %xwtG:IKEV
{ j>O!|V
if(sHeader.equals("Content-Length")) o=Kd9I#
{ KD8,a+GL
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); z#srgyLt
break; %xN91j["
} !?GW<Rh
} LE+#%>z>
else 7eyx cr;z
break; l\&Tw[O
} . L]!*
} L@~0`z:>iP
catch(IOException e){e.printStackTrace ();} #D Oui]
catch(Exception e){e.printStackTrace ();} M~djX} #\
jGKI|v4U(
;<s0~B#9}
Utility.log(nFileLength); g$9s}\6B
KiMEd373-
&}b-aAt
return nFileLength; g:[yA{Eh
} T3/Gl6f
0t0m?rVW
l\t<_p/I)^
//保存下载信息（文件指针位置） dQPW9~g8Hg
private void write_nPos() HAGpM\Qa
{ @l&>C#K\
try{ :cE~\BS&
output = new DataOutputStream(new FileOutputStream(tmpFile)); `j(-y`fo
output.writeInt(nStartPos.length); ^r^) &]
for(int i=0;i<nStartPos.length;i++) O`'r:&#W
{ 1y6{3AZm<
// output.writeLong(nPos); 5H/D~hr&
output.writeLong(fileSplitterFetch.nStartPos); 3/RNStd<L!
output.writeLong(fileSplitterFetch.nEndPos); ),U>AiF]
} $w ,^q+
output.close(); j%Z%_{6Ds*
} S!.H _=z%p
catch(IOException e){e.printStackTrace ();} <iznB8@
catch(Exception e){e.printStackTrace ();} oz?pE[[tm
} W< :7z
mI3 \n
8Rd*`]@[pk
//读取保存的下载信息（文件指针位置） (-hGb:
private void read_nPos() Q1u/QA:z7
{ yxL(mt8
try{ HpR(DG) ?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); nB#XQ8Nzx^
int nCount = input.readInt(); ]"-c?%L
nStartPos = new long[nCount]; MI|anM
nEndPos = new long[nCount]; S2"HE`
for(int i=0;i<nStartPos.length;i++) nQ^ c{Bm:
{ yq\p%z$:
nStartPos = input.readLong(); |eFce/
nEndPos = input.readLong(); C?7I(b:
} ^Z:qlYZ
input.close(); *waaM]u
} H4IJLZ3G
catch(IOException e){e.printStackTrace ();} U9:I"f,
catch(Exception e){e.printStackTrace ();} }^n346^
} pJ3Yjm[l
9*j$U$:'
[BKX$A:Y
private void processErrorCode(int nErrorCode) j#YPo
{ (2p<I)t
System.err.println("Error Code : " + nErrorCode); cP`[/5R
} H+F>#
K}9c$C4
\"?5CHz*
//停止文件下载 Z-rHYfa4
public void siteStop() TAKvE=a;
{ hScC<=W
bStop = true; .{ r %C4q9
for(int i=0;i<nStartPos.length;i++) @_C?M5v
fileSplitterFetch.splitterStop(); p2uZ*sY(D
pn-`QB:{h
8;1,saA_9
} !t!\b9=
} b[`fQv$G
//负责部分文件的抓取 _!Ir|j.A
**FileSplitterFetch.java ;A;FR3=)
*/ "vN~7%
package NetFox; hYEUiQ
.GOF0puiM
&ub0t9R
import java.io.*; @w5x;uB|%G
import java.net.*; ]U)Yg
9a3mN(<
}+ZZO0
public class FileSplitterFetch extends Thread { U@<]>.$
U6yZKK
ud:5_*
String sURL; //File URL VDy\2-b8d
long nStartPos; //File Snippet Start Position 'fr~1pmx#3
long nEndPos; //File Snippet End Position t p<wMrq<
int nThreadID; //Thread's ID mPS27z(
boolean bDownOver = false; //Downing is over &(i_s
boolean bStop = false; //Stop identical ;{f4E)t 7
FileAccessI fileAccessI = null; //File Access interface qttJ*zu
_0EKE
}>< v7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException qpXsQim$~
{ 8a,pDE
this.sURL = sURL; L@>$ Aw
this.nStartPos = nStart; x4%1P w
this.nEndPos = nEnd; [ T!0ka
nThreadID = id; (hFyp}jkk
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $hq'9}ASOL
} SVJt= M
RSK5 }2
$Z[W}7{pt#
public void run() )H|cri~D
{ c-q=Ct
while(nStartPos < nEndPos && !bStop) 8D6rShx =
{ G"D=ozr
WI}cXXUKm0
caXSt2|'
try{ &$8YW]1M
URL url = new URL(sURL); ~zph,bk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o GN*p_g
httpConnection.setRequestProperty("User-Agent","NetFox"); m*H' Cb
String sProperty = "bytes="+nStartPos+"-"; ?:+sjHzXT
httpConnection.setRequestProperty("RANGE",sProperty); \<0xg[
Utility.log(sProperty); c01i!XS
G7uYkJO
;?.w!|6
InputStream input = httpConnection.getInputStream(); UNJAfr P
//logResponseHead(httpConnection); 1Zt>andBF
\^]*T'>b
?`T-A\A=
byte[] b = new byte[1024]; ^SC2k LI
int nRead; q!4eVg*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 35/K9l5
{ `|WEzW~
nStartPos += fileAccessI.write(b,0,nRead); p`/c&}
//if(nThreadID == 1) }C!g x6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :hFKmoy#
} 3:"w"0[K3
~Y3X*
i.Z iLDs\7
Utility.log("Thread " + nThreadID + " is over!"); 20?@t.aMp
bDownOver = true; pi;'!d[l%
//nPos = fileAccessI.write (b,0,nRead); =:;K nS
} 0I['UL^!F
catch(Exception e){e.printStackTrace ();} X<mlaXwrA
} k<}3_
} t+Au6/Dx?
|*n B2
,Vfjt=6]}
//打印回应的头信息 )];Bo.QA
public void logResponseHead(HttpURLConnection con) FL E3LH
{ o8h`9_
for(int i=1;;i++) 7ro&Q%
{ pj#ls
String header=con.getHeaderFieldKey(i); Z~1uyr(
if(header!=null) uZe"M(3r$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); bZWdd6
Utility.log(header+" : "+con.getHeaderField(header)); |qz&d=>
else {@ Z=b5/P
break; oe<DP7e
} TXo`P_SE
} kJK*wq]U6
Wn-'iD+9<
kwUy^"O
public void splitterStop() w0^}c8%WR
{ SW)jDy
bStop = true; qT~a`ou:
} \wF-[']N
W5,&*mo
r1[c+Hy
} #\Zr$?t|V
K$I`&M(
XNJ3.w:R
/* Zygu/M6
**FileAccess.java 6u>]-K5
*//文件访问(定位，写) K.Tob,5`
package NetFox; i ?PgYk&}
import java.io.*; >!Dp'6
q~`dxq`}
Z rv:uEl
public class FileAccessI implements Serializable{ o3JSh=
"h-ZwL
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _p^$.\k"
RandomAccessFile oSavedFile; Jq?Fi'2F%
long nPos; L%jIU<?Z7
hBi/lHu'
a:Nf+t
public FileAccessI() throws IOException |]5`T9K@b#
{ "x3x$JQZy
this("",0); D)tL}X$
} "!ks7:}v
foUB/&Ee
0<93i
public FileAccessI(String sName,long nPos) throws IOException -9Dr;2\
{ :!Nx'F9a
oSavedFile = new RandomAccessFile(sName,"rw"); #>6Jsnv1
this.nPos = nPos; X0Wx\xDg[
oSavedFile.seek(nPos); +ZOKfX
} =Cd{bj.8
SY.ZEJcv
<nTZs`$LwL
public synchronized int write(byte[] b,int nStart,int nLen) zx5#eMD
{ |DYgc$2pN
int n = -1; G=]ox*BY
try{ td7Of(k'
oSavedFile.write(b,nStart,nLen); &0i$Y\g
n = nLen; Fw:_O2
} e07u@_'^
catch(IOException e) >gDeuye
{ !jvl"+_FV
e.printStackTrace (); 3CH>!QOA
} fN/;BT
(&Rql7](8
7>=
return n; 0SQrz$y
} }Ogb|8
bh(}f.@ 9
?)T@qn+
} @]!9;?so
6_:I~TTX
Fv*Et-8tN5
/* e_"m\e#N
**SiteInfoBean.java $01csj
*/ 1_};!5$.
package NetFox; 1tLEKSo+
--EDr>'D5P
S+"Bq:u"
public class SiteInfoBean { TOhWfl;
mfG m>U
IEfYg(c0U
private String sSiteURL; //Site's URL {1qr6P,"
private String sFilePath; //Saved File's Path YmpaLZJ
private String sFileName; //Saved File's Name JfY(};&
private int nSplitter; //Count of Splited Downloading File S'\e"w
Npi)R)
=?Ui(?tI
public SiteInfoBean() Kv2S&P|jXM
{//nSplitter的缺省值为5 |]9L#
//default value of nSplitter is 5 zk"8mTg
this("","","",5); iCLH
} TW|- 0
vZW[y5
8+J>jZ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) r6kJV4I=re
{ J.'%=q(Sb
sSiteURL= sURL; ANNVE},
sFilePath = sPath; 9ln=f=
sFileName = sName; q#@r*hl
this.nSplitter = nSpiltter; t|mK5aR4
bLSc=f&
^/6P~iK'
} I)yF!E &
k~gOL#$
XK\3"`kd
public String getSSiteURL() CBoCT3@~
{ PXqG;o*Q*?
return sSiteURL; jFJ}sX9]
} <_ENC>NP
shw"TF>?zG
iPkCuLQ}
public void setSSiteURL(String value) {z\K!=X/
{ lZuH:AH
sSiteURL = value; rwVp}H G
} reNf?7G+m
[sjkm+ ?
% P Ex
public String getSFilePath() EZN!3y|m
{ #]6{>n1*+w
return sFilePath; yCA8/)>Gm
} KGcjZx04!
Sb> &m
kiyc^s
public void setSFilePath(String value) Ix}6%2\
{ /Q3\6DCl
sFilePath = value; 0Sz[u\w
} s5rD+g]E`
@"MQ6u G>
/s~S\dG
public String getSFileName() EEnl'
{ /aMOZ=,q}
return sFileName; aWlIq(dU
} hxK;f
\xbUr`WBY
\hZ%NLj
public void setSFileName(String value) ZZ!">AN`^
{ KbtV>
sFileName = value; dzBP<Xyh
} &b`W<PAc?4
D4,>g )B
:)D7_[i
public int getNSplitter() DJ@n$G`^^
{ (S?Y3l|
return nSplitter; 5QLK
} as!a!1
($kw*H{Ah^
mHHlm<?]
public void setNSplitter(int nCount) BkGExz
{ "I)zi]vk
nSplitter = nCount; ,!b<SQ5M
} |5tZ*$nGa
} (or"5}\6-
?q9]H5\
[#q]B=JB
/* -PAEJn5$O
**Utility.java |Ia9bg'1U
*/ p/?o^_s
package NetFox; 8"9&x} tl-
uT4|43< G
F{!pii5O9
public class Utility { No} U[u.O
z__?kY
|Z<\kx
public Utility() n)98NSVDbT
{ ,`Y$}"M4
"mf$E|
jt on\9
} ESIP+
U`i5B;k}-
//线程睡眠 +q'1P}e
public static void sleep(int nSecond) xNf}f 9l
{ NFZ(*v1U
try{ j*G: 8Lg
Thread.sleep(nSecond); robg1
} 0^gY4qx[u
catch(Exception e) 1wKXOy=v0
{ ^]nLE]M
e.printStackTrace (); 7>__ fQu
} HDhISPg
} hc[ K VLpS
5tQz!M
//日志 ;_e9v,
public static void log(String sMsg) JEp)8{.bW8
{ n jWe^
System.err.println(sMsg); o+A1-&qhN
} W&*&O,c
?gl&q+mv
G/<zd)
public static void log(int sMsg) #BUq;5
{ 7TMq#Pb
System.err.println(sMsg); gCb+hQq\
} >8"Svt$
} M% \T5
DFK@/.V
_TOWqV^
/* J8alqs7
**TestMethod.java + U5Q/g
*/ ,Gt!nm_
package NetFox; 3!{imQT
oQ<[`.s
6M*z`B{hV
public class TestMethod { 0%rDDB
Q+T#J9Y
q`'f /CS
public TestMethod() OuTV74
{ ///xx/weblogic60b2_win.exe iY,C0=n5Y
try{ pT]hPuC
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); j8` B
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "/aZ*mkjfJ
SiteFileFetch fileFetch = new SiteFileFetch(bean); PN l/}'
fileFetch.start(); 0\tac/
} AygdAg'\
catch(Exception e){e.printStackTrace ();} Ayw_LCUD
]`&_!T
bE !SW2:M
} q!z"YpYB
SH{@yS[c!
xz8e1M
public static void main(String[] args) _Sr7b#)o
{ iWf+wC|
new TestMethod(); G&g;ROgY
} 0+FPAqX
} .n]"vpWm[
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