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)); ;wwhW|A
} 8!2NZOZOS
for(int i=0;i<nEndPos.length-1;i++) 9\ZlRYnc=
{ Yf:xM>.%
nEndPos = nStartPos[i+1]; };6[Byf
} DXu#07\
nEndPos[nEndPos.length-1] = nFileLength; {R%v4#nk
} Kmc*z (Q
} ~Mbo`:>(4v
NBEcx>pma
1wP#?p)c
//启动子线程 h}r*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; rCU f,)
for(int i=0;i<nStartPos.length;i++) k,wr6>'Vt
{ GjN/8>/
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Vp{! Ft8>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), GEj/Z};;[b
nStartPos,nEndPos,i); QH@?.Kb_qU
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "| cNY_$&s
fileSplitterFetch.start(); d 4w+5H"u
} FDBj<uXfM|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ts%XjCN[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;#$ 67G$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", WP[h@#7<
nEndPos = " + nFileLength); 4>eY/~odq]
// fileSplitterFetch[nPos.length-1].start(); !)gTS5Rh:
6$$4!R-
c<-F_+[
//等待子线程结束 lx_jy>$}r
//int count = 0; n6D9f~8"
//是否结束while循环 1><@$kVMm~
boolean breakWhile = false; y|X</3w
Z BjyQ4h
hr3RC+ y
while(!bStop) 2f>G
{ "[M,PI!B
write_nPos(); Gu[G_^>
Utility.sleep(500); lz=$Dz
breakWhile = true; LA &W@
\) DJo
)7!q>^S{B
for(int i=0;i<nStartPos.length;i++) Jm8{@D%
{ gZ vX~
if(!fileSplitterFetch.bDownOver) 9n4vuBgv
{ 5-'jYp/
breakWhile = false; uqe{F+;8&
break; 7i^7sT8t
} h0}r#L
} 4UwXrEQp
if(breakWhile) c6/+Ye =h
break; Wy1#K)LRb
&Ui*w%
IxN0m7
//count++; _2uRY
//if(count>4) _+Tq&,_:o
// siteStop(); ^ [FK<9
} lh^-L+G:Ok
L3}n(KAJj
M~%~y`D^
System.err.println("文件下载结束！"); N3/G6wn
} vEQw`OC
catch(Exception e){e.printStackTrace ();} qJV2x.!
} 'YQ^K`lV
;Z>u]uK4+
.axJ'*~W
//获得文件长度 3sr>?/>:
public long getFileSize() `;KU^dH
{ CB V(H$d
int nFileLength = -1; ,liFo.kT8%
try{ w_zUA'n+
URL url = new URL(siteInfoBean.getSSiteURL()); ZqT8G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R\DdU-k
httpConnection.setRequestProperty("User-Agent","NetFox"); J)(KGdk
{2jetX`@h
<X@XbM
int responseCode=httpConnection.getResponseCode(); w7Fz(`\
if(responseCode>=400) )}ygzKEa
{ }U <T>0
processErrorCode(responseCode); uWm,mGd9
return -2; //-2 represent access is error G bW1Lq&"
} t~_j+k0K#
`zf,$67>1
2I:x)
String sHeader; wxC&KrRF
(4:&tm/;
^G:}%4
for(int i=1;;i++) j}P xq
{ ~V#MI@]V~
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); a^:on?:9
//Utility.log(in.readLine()); DJ&ni`
sHeader=httpConnection.getHeaderFieldKey(i); 9Q\CJ9
if(sHeader!=null) 4wLN#dpeEy
{ iYbp^iVg
if(sHeader.equals("Content-Length")) NMaZ+g!t(
{ x<&2`=
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Std?p{ i
break; $H\[yg>4
} PSCzeR
} 6(#fGH&[
else d_t>
break; n*(9:y=l1
} GjVq"S
} 8w,+Y]X<P[
catch(IOException e){e.printStackTrace ();} dyH<D5
catch(Exception e){e.printStackTrace ();} ~H<oqk:O-
qW~Z#Si
>WYiOXYv
Utility.log(nFileLength); LWH(bs9U
7TDt2:;]
R'Gka1v
return nFileLength; VkFvV><"
} MTnW5W-r9
#6g9@tE
>z{*>i,m1
//保存下载信息（文件指针位置） oe (})M
private void write_nPos() 4KbOyTQ
{ 6_UCRo5h%
try{ TRLz>mQ
output = new DataOutputStream(new FileOutputStream(tmpFile)); nK!yu?mS
output.writeInt(nStartPos.length); e6G=Bq$
for(int i=0;i<nStartPos.length;i++) 1gK<dg
{ c>SFttbU
// output.writeLong(nPos); 5Z8Zb.
output.writeLong(fileSplitterFetch.nStartPos); +qPpPjG;
output.writeLong(fileSplitterFetch.nEndPos); ,\){-H/n
} J#1-Le8@
output.close(); U-~6<\Mf
} $ ,:3I*}be
catch(IOException e){e.printStackTrace ();} w^Mj[v#
catch(Exception e){e.printStackTrace ();} 2SjH7 '
} z (1zth
dM-qd`
!O*'mX
//读取保存的下载信息（文件指针位置） kdgU1T@y.
private void read_nPos() 0f_+h %%=
{ 5{zmuv:
try{ \C{Dui)F
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7dm:L'0
int nCount = input.readInt(); H[WsHq;T+9
nStartPos = new long[nCount]; Uzi.CYVs%
nEndPos = new long[nCount]; ol[sX=5 *
for(int i=0;i<nStartPos.length;i++) UO1WtQyu,H
{ FRBW(vKE
nStartPos = input.readLong(); v|K,
nEndPos = input.readLong(); !g`^<y!
} 54lU~ "
input.close(); kT@m*Etr{
} DPWt=IFU
catch(IOException e){e.printStackTrace ();} l1M %
catch(Exception e){e.printStackTrace ();} AfAlDM'
} h0cdRi
Vx Vpl@
(^{tu89ab
private void processErrorCode(int nErrorCode) '3i,^g0?t0
{ ]2_b_ok
System.err.println("Error Code : " + nErrorCode); _ww>u""B~
} m}-*B1
S3?Bl'
]NEr]sc-"F
//停止文件下载 cD%_+@GaU
public void siteStop() S|jE1v"L
{ L2sUh+'|
bStop = true; o^efeI
for(int i=0;i<nStartPos.length;i++) gTM*td(~^
fileSplitterFetch.splitterStop(); [ pe{,lp
7^oO N+=d
|#b]e|aP
} 5V $H?MW>
} mi';96
//负责部分文件的抓取 LJ8 t@ui
**FileSplitterFetch.java gh?3[q6
*/ Nc da~h Q
package NetFox; g7UZtpLTm
XfYbWR
MwuRxeRO-
import java.io.*; WR.>?IG2E
import java.net.*; >iV2>o_
+QW|8b
'=WPi_Z5:C
public class FileSplitterFetch extends Thread { ez-jVi-Fi
w-j^jU><3
L-9AJk>V
String sURL; //File URL c%+_~iBUN
long nStartPos; //File Snippet Start Position o#Viz:
long nEndPos; //File Snippet End Position <G_71J`MLC
int nThreadID; //Thread's ID zk;'`@7
boolean bDownOver = false; //Downing is over 5Ic'6AIz
boolean bStop = false; //Stop identical @*<`*W
FileAccessI fileAccessI = null; //File Access interface 'PqKb%B|
~Fe$/*v
<-h[I&."
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {y%|Io`P
{ '>^!a!<G
this.sURL = sURL; !jTxMf
this.nStartPos = nStart; h}U>K4BJ
this.nEndPos = nEnd; Wt M1nnJp
nThreadID = id; B'v~0Kau
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @kPe/j/[1
} fq[1|Q
1xD?cA\vu
K%g_e*"$
public void run() | 9 <+!t\
{ 1KadT7<0}
while(nStartPos < nEndPos && !bStop) @$|8zPs
{ tch;_7?
M{jJ>S{g
4M)oA|1w
try{ $vLGX>H
URL url = new URL(sURL); VvUP;o&/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i*)BFV_-
httpConnection.setRequestProperty("User-Agent","NetFox"); VZ]}9k
String sProperty = "bytes="+nStartPos+"-"; tc|PN+v;
httpConnection.setRequestProperty("RANGE",sProperty); CklIrD{
Utility.log(sProperty); d6f T
UlMc8z
b:Tv Ta
InputStream input = httpConnection.getInputStream(); moD)^':.
//logResponseHead(httpConnection); 6W/uoH=;
;w<r/dK
O9P4r*prA
byte[] b = new byte[1024]; 0<)Ep~!
int nRead; [85b+SKW
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) C({r1l4[D
{ lyzM?lK-
nStartPos += fileAccessI.write(b,0,nRead); .3CQFbHF
//if(nThreadID == 1) `$Y%c1;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <64#J9T^
} _&RGhA
fP/;t61Z
;3\'}2^|l
Utility.log("Thread " + nThreadID + " is over!"); 8xt8kf*k
bDownOver = true; 4jw q$G
//nPos = fileAccessI.write (b,0,nRead); _/NPXDL
} c{3P|O&.
catch(Exception e){e.printStackTrace ();} U.Fs9F4M#
} F*JbTEOn
} jGUegeq
}p>l,HD
s[;1?+EI
//打印回应的头信息 "9IR|
public void logResponseHead(HttpURLConnection con) X2mZ~RB(p
{ pD]2.O
for(int i=1;;i++) )S9}uOG#
{ 4xF}rm
String header=con.getHeaderFieldKey(i); cp&1yB
if(header!=null) ge]Z5E(1
//responseHeaders.put(header,httpConnection.getHeaderField(header)); tP89gN^PA|
Utility.log(header+" : "+con.getHeaderField(header)); }\QXPU{UVd
else -U{!'e8YiN
break; ETm:KbS
} ~g}blv0q+B
} lXRB"z
MM*9Q`cB
E <N%
public void splitterStop() ]Na;b
{ Ch)E:Dvq6
bStop = true; "8 ?6;!,
} 3$3%W<&^
bD=R/yA
;!j/t3#a
} }O\g<ke:u
&MBm1T|Y
kyf(V)APPu
/* x@*?~1ai
**FileAccess.java zp\_5[qJ;
*//文件访问(定位，写) Pf~0JNnc
package NetFox; *G[` T%g
import java.io.*; Y=@iD\u
75iudki
& j*Ylj}
public class FileAccessI implements Serializable{ {KSy I#
%reW/;)l{
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~FVbL-2
RandomAccessFile oSavedFile; L+Gi
long nPos; uT YG/O
A:\_ \B%<
e 8^%}\F
public FileAccessI() throws IOException .*?)L3n+t
{ f[q_eY
this("",0); gX(8V*os^
} x[R?hS,0t
X;v{,P=J
4M;S&LA
public FileAccessI(String sName,long nPos) throws IOException Pr,C)uch
{ }Qh%Z)
oSavedFile = new RandomAccessFile(sName,"rw"); knzQ)iv&&
this.nPos = nPos; ]''tuo2g8
oSavedFile.seek(nPos); bd3>IWihp
} #fFD|q
qnzNJ_ `R
Q'[~$~&`
public synchronized int write(byte[] b,int nStart,int nLen) ?sxf_0*
{ I#xhmsF
int n = -1; r#d]"3tH
try{ Xy9'JVV6
oSavedFile.write(b,nStart,nLen); ;1k_J~Qei
n = nLen; Q;@w\_OR
} HS|x
catch(IOException e) :I^4ILQCD
{ M#yUdl7d
e.printStackTrace (); qJ$S3B
} xzRC %
]@qD4:
[n +(
return n; cGWL'r)P
} 17VNw/Y
0.#%KfQ
zu1gP/
} !9^GkFR6n
+EZr@
F|&mxsL
/* eXdH)|l,\
**SiteInfoBean.java *T{KpiuP
*/ '=IuwCB|;
package NetFox; ^fM=|.?
l4OPzNc'
*}LQZFrnX
public class SiteInfoBean { _K~?{".
+*RpOtss
+@PZ3 [s
private String sSiteURL; //Site's URL K$M,d- `b
private String sFilePath; //Saved File's Path & aF'IJC
private String sFileName; //Saved File's Name FFH{#|_1
private int nSplitter; //Count of Splited Downloading File 94XRf"^
) |hHbD^V
Uzk_ae
public SiteInfoBean() cr{dl\Na
{//nSplitter的缺省值为5 hy:K) _
//default value of nSplitter is 5 bre6SP@
this("","","",5); dRTpGz
} <pUc( tPoz
j MA%`*r
_[ `"E'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 98WJ"f_ #
{ !v3wl0
sSiteURL= sURL; 4W+nSv
sFilePath = sPath; gwYTOs^
sFileName = sName; g:"Hg-s
this.nSplitter = nSpiltter; wD[qE
wSs78c=
;<`
} 3lNw*M|")
uMP&.Y(
L^nS%lm
public String getSSiteURL() Xg97[I8/
{ < YuI}d~'
return sSiteURL; \y/+H
} JDC,]
5TdI
W&^2Fb
public void setSSiteURL(String value) M~!LjJg;
{ B?_ujH80m
sSiteURL = value; m<22E0=g
} Q&9& )8-
@aGS~^Uh
Mq,_DQ
public String getSFilePath() Eb9M;u
{ P^*gk P
return sFilePath; :Ee5:S
} fKT(.VNq5
GgjBLe=C
6d/b*,4[
public void setSFilePath(String value) 3!B3C(g
{ HjN )~<j
sFilePath = value; 6_a.`ehtj<
} 5(OF~mX#
uO-R:MC
/h%MWCZWm^
public String getSFileName() oDas~0<oh
{ 8%#uZG\}
return sFileName; BF6H_g
} ihhnB
E0S[TEDa]
sw &sF
public void setSFileName(String value) XC{(O:EG
{ }c,}+{q
sFileName = value; AuYi$?8|5
} I!Za2?
`P4qEsZE>`
gf2w@CVF>=
public int getNSplitter() )+9D$m=P;
{ rQ$A|GJL
return nSplitter; cWM|COXL+
} I@q>ES!1H
g^En6n)
aa1XY&G"!
public void setNSplitter(int nCount) OiY2l;68
{ c#;LH5KI
nSplitter = nCount; "Hjw
} 4%j&]PASa1
} |qNrj~n@
LGCL*Qbsg
Sb[rSczS~
/* @;,O V&XYn
**Utility.java jIc;jjAF
*/ zFuUv_t
package NetFox; [%nG_np
z(orA} [
emS+%6U
public class Utility { k*c:%vC!
[I4FU7mpH
MgMLfgt"V
public Utility() 7<^D7
{ KwQO,($,]
)SUN+YV^
Q84KU8?d
} ,em6wIq,
W@$p'IBwm
//线程睡眠 ;+b}@e
public static void sleep(int nSecond) ]:E]5&VwV}
{ '\*Rw]bR|
try{ rrwsj`
Thread.sleep(nSecond); TcfBfscU
} Jp-ae0 Ewa
catch(Exception e) X)f"`$
{ |f?C*t',
e.printStackTrace (); *u{.K:.I
} 1v\-jM"
} IfXLnD^||
fF[g%?w
//日志 rw\4KI@ L
public static void log(String sMsg) H@j^,
{ b);}x1L.T
System.err.println(sMsg); i)(QNpv
} Ju9v n44
^:)&KV8D|
wbS++cF<
public static void log(int sMsg) 610k#$
{ ^&rbI,D
System.err.println(sMsg); S~Hj. d4/
} $^0YK|F
} Csc2yI%3
1aT$07G0
d|NNIf
/* d<3"$%C
**TestMethod.java z"O-d<U5
*/ e#OU {2X
package NetFox; [1UqMkXtf
6kuSkd$.
$WPN.,7
public class TestMethod { YWZF*,4
Mk9kGP%
x/S%NySG
public TestMethod() tQ}gBE63
{ ///xx/weblogic60b2_win.exe z*[Z:
try{ j{Fo 6##
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~3YNHm6V
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5k(#kyP
SiteFileFetch fileFetch = new SiteFileFetch(bean); 68!fcK
fileFetch.start(); vxt^rBA
} ,RHHNTB("
catch(Exception e){e.printStackTrace ();} A{o{o++
mHMej@
vPsX!m[#
} KE3v3g<
o<'gM]$
]/']{*T1
public static void main(String[] args) D_)vGvv3;.
{ T:&+#0<
new TestMethod(); N.`]D)57
} @&W?e?O ~G
} ~GeYB6F
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