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)); y:$qX*+9e
} \T<F#a
for(int i=0;i<nEndPos.length-1;i++) i;]# @n|
{ !Icznou\
nEndPos = nStartPos[i+1]; DKem;_6OQ
} upZc~k!1\
nEndPos[nEndPos.length-1] = nFileLength; aUc#,t;Qd
} <&O*' <6C
} a|4D6yUw|
L>E{~yh
B^zg#x#8
//启动子线程 Lyn{Uag
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; P_8!Gp
for(int i=0;i<nStartPos.length;i++) Z02EE-A
{ xw_$1 S
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WJa7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), F:jtzy"
nStartPos,nEndPos,i); 9xw"NcL
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dBovcc
fileSplitterFetch.start(); H_x}-
} V:P]Ved
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |S@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #8M^;4N>[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }|[0FP]v
nEndPos = " + nFileLength); hy%5LV<(
// fileSplitterFetch[nPos.length-1].start(); Vjo[rUW
;1nXJ{jKw
gae=+@z
//等待子线程结束 ZPq.|6&
//int count = 0; gV\Y>y4v
//是否结束while循环 ZfVY:U:o>
boolean breakWhile = false; 6|3 X*Orn
ohJDu{V
M}CxCEdDB]
while(!bStop) !Yn#3c
{ 6w m-uu
write_nPos(); D/4]r@M2c
Utility.sleep(500); I!1+#0SG
breakWhile = true; iTO Y
$XMpC{
l=Pw yJ
for(int i=0;i<nStartPos.length;i++) ,2^A<IwR
{ JTBt=u{6^
if(!fileSplitterFetch.bDownOver) <}8G1<QZ'.
{ S0:Oep
breakWhile = false; k&f/f
break; ]F>#0Rdc
} CAom4Sp'
} {TJBB/B1
if(breakWhile) `D=`xSEYl
break; sN?Rx}
?YV# K
`T7TWv"M
//count++; /4;A.r`;
//if(count>4) I2SH j6-
// siteStop(); hDZyFRg
} Ef?|0Gm
Lz-|M?(
8d Fqwpw8
System.err.println("文件下载结束！"); YhmveV
} WDV=]D/OE
catch(Exception e){e.printStackTrace ();} ;8eGf'
} gVh&c4
pBv,,d`
^>Z7."uGY
//获得文件长度 N$C+le
public long getFileSize() Eaxsg
{ jAy2C&aP
int nFileLength = -1; Q{'4,J-w
try{ *vIP\NL?H
URL url = new URL(siteInfoBean.getSSiteURL()); 2*#i/SE_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); PN<VqtW
httpConnection.setRequestProperty("User-Agent","NetFox"); EfpMzD7/(
Y}t)!}p$r
XIZN9/;
int responseCode=httpConnection.getResponseCode(); *o:J 4'
if(responseCode>=400) +_bxza(ma{
{ JEWc{)4QD
processErrorCode(responseCode); aot2F60J,
return -2; //-2 represent access is error @V5i
} @H~oOf
`"yxmo*0
Iu`S0#+
String sHeader; LYd:S
5jwv!L<n
bqA`oRb\
for(int i=1;;i++) VmQ'
{ mEi(DW)(
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Qy[S~D_
//Utility.log(in.readLine()); =&9c5"V&
sHeader=httpConnection.getHeaderFieldKey(i); |pG0 .p4
if(sHeader!=null) BOcD?rrZ0
{ -KfK~P3PF
if(sHeader.equals("Content-Length")) 4e AMb
{ >b=."i
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ONDO xXs
break; G%>[7]H
} Wq5}LO)
} oJ3(7Sz
else +r;t]
break; tCGx]\
} &k)v/
} FPF$~ sX
catch(IOException e){e.printStackTrace ();} /3SEu(d!
catch(Exception e){e.printStackTrace ();} N!wuBRWR
_`^AgRE
d6JW"
Utility.log(nFileLength); qz3 Z'
chKEGosbF
"p|.[d
return nFileLength; 8-k`"QI=
} EQd<!)HZ
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19y,O0# _
//保存下载信息（文件指针位置） 3#dz6+
private void write_nPos() C#yRop_d]o
{ FBB<1({A
try{ G}+@C]
output = new DataOutputStream(new FileOutputStream(tmpFile)); {I$iD
output.writeInt(nStartPos.length); hwL`9.w
for(int i=0;i<nStartPos.length;i++) Z2})n -
{ [XDV-6KCE.
// output.writeLong(nPos); ">3t+A
output.writeLong(fileSplitterFetch.nStartPos); 1i~q~O,
output.writeLong(fileSplitterFetch.nEndPos); Z}>F V~4
} _(8#
output.close(); Yk?q\1
} B&B:P
catch(IOException e){e.printStackTrace ();} DQP!e6Of
catch(Exception e){e.printStackTrace ();} WSxoGly
} srAWet
~TS!5Wiv
8]b;l; W5
//读取保存的下载信息（文件指针位置） \9` ~9#P
private void read_nPos() ?a% F3B
{ cHT\sJo`l
try{ y {Bajil
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +PADy8
int nCount = input.readInt(); %Y=r5'6l
nStartPos = new long[nCount]; |?Edk7`
nEndPos = new long[nCount]; 8OV=;aM?{
for(int i=0;i<nStartPos.length;i++) G6W|l2P!
{ PLz+%L;{
nStartPos = input.readLong(); K\fD';
nEndPos = input.readLong(); Ay 4P_>^
} ")vtS}Ekt
input.close(); /!?Tv8TPp
} ;|?_C8
catch(IOException e){e.printStackTrace ();} @{_X@Wv4iV
catch(Exception e){e.printStackTrace ();} 4;AQ12<[1
} (?^F }]
^p9V5o
Tsb}\
private void processErrorCode(int nErrorCode) N wNxO
{ \7*|u
System.err.println("Error Code : " + nErrorCode); UF-'(
} ]a&riPh"
zx2`0%Q
K\;4;6g
//停止文件下载 7.ein:M|CB
public void siteStop() V59!}kel1%
{ Db*b"/]
bStop = true; Y,}h{*9Kd
for(int i=0;i<nStartPos.length;i++) cNmAr8^}
fileSplitterFetch.splitterStop(); d-e/0F!
UYJ>L
+}?%w|8||s
} Al8Dw)uG{
} $ ~%Y}Xt*
//负责部分文件的抓取 F {L#
**FileSplitterFetch.java ocK4Nxs
*/ s[h;9 I1w
package NetFox; ftPhE)i
^lZ7%6
pKj:)6t"
import java.io.*; "j?xgV
import java.net.*; !> +Lre@
%5KK#w "
v@yqTZ
public class FileSplitterFetch extends Thread { c!wRq4
JBJ?|}5k4c
u?MhK#Mr
String sURL; //File URL Hf_ pe
long nStartPos; //File Snippet Start Position sn^ 3xAF
long nEndPos; //File Snippet End Position .|07IH/Di{
int nThreadID; //Thread's ID VWK/(>TP
boolean bDownOver = false; //Downing is over CL7/J[TS
boolean bStop = false; //Stop identical : fYfXm
FileAccessI fileAccessI = null; //File Access interface &1^~G0Rh\
OGJrwl
+MaEet
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException GeB&S!F
{ ?f'`b<o
this.sURL = sURL; \_R<Q?D+
this.nStartPos = nStart; zZRLFfz<9
this.nEndPos = nEnd; tB`"gC~
nThreadID = id; f-[.^/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Ps\4k#aOv
} R_GA`U\ {
-X%twy=
U"Bge\6x=
public void run() 8,vP']4r%
{ fSVM[
while(nStartPos < nEndPos && !bStop) UukY9n];]
{ noa+h<vGb
7SYe:^Dx
2h*aWBLk
try{ %P<fz1
URL url = new URL(sURL); h,BPf5\S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $t"QLsk0
httpConnection.setRequestProperty("User-Agent","NetFox"); +N+117m
String sProperty = "bytes="+nStartPos+"-"; mr#.uhd.z
httpConnection.setRequestProperty("RANGE",sProperty); Fec4#}|
Utility.log(sProperty); ^z,B}Nz
S["r @<
ip{b*@K
InputStream input = httpConnection.getInputStream(); XfMUodV-OZ
//logResponseHead(httpConnection); <'sm($.2
%_p]6doF
h]z8.k2n
byte[] b = new byte[1024]; ZTfW_0
int nRead; gYGoJH1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) z4(\yx
{ Yqo@ g2g
nStartPos += fileAccessI.write(b,0,nRead); +cmi?~KS*
//if(nThreadID == 1) _]Ob)RUVH
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qyKR]%yzi
} =+DhLH}8
P2s\f;Dwr
mA,{E-T
Utility.log("Thread " + nThreadID + " is over!"); )*uotV
bDownOver = true; ;WYzU`<g
//nPos = fileAccessI.write (b,0,nRead); #sjGju"#_
} $kmY[FWu?
catch(Exception e){e.printStackTrace ();} l"X,[
} &c&TQkx
} y,n.(?!*
xpuTh"ED
eA?|X|
//打印回应的头信息 T7/DH
public void logResponseHead(HttpURLConnection con) Zj ^e8u=T
{ \j wxW6>
for(int i=1;;i++) p*YV*Arv
{ DyZ6&*s$
String header=con.getHeaderFieldKey(i); 0 .T5% _/
if(header!=null) 9X33{
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ow5VBw(
Utility.log(header+" : "+con.getHeaderField(header)); UMD\n<+cG,
else x00'wY|
break; FdEUZ[IT`{
} %Q]thv:
} ,g"JgX
2dJE`XL
Rx&.,gzj[
public void splitterStop() A8S9HXL
{ 3syA$0TZt
bStop = true; a;~< iB;3"
} OuWRLcJ!
ScVbo3{m*T
j!k$SDA-
} Nqd9)WQ
N,VI55J:y>
!a!4^zqp
/* {dE(.Z?]!#
**FileAccess.java PGYx]r
*//文件访问(定位，写) +tg${3ti_
package NetFox; Rm$(X5x>o
import java.io.*; >nvK{6xR:
!>Q\Y`a,*
^4\0,>
public class FileAccessI implements Serializable{ e(b$LUV
r6aIW8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2* TIr
RandomAccessFile oSavedFile; ('dbMH\O
long nPos; Tl]yl$
w6Mv%ZO_
TMsCl6dB
public FileAccessI() throws IOException tBl(E
{ f;,*P,K
this("",0); 0blbf@XA
} 9}fez)m:g0
TA:#K
gCVOm-*:
public FileAccessI(String sName,long nPos) throws IOException $cm9xW&
{ F1M:"-bda
oSavedFile = new RandomAccessFile(sName,"rw"); pbWjTI$
this.nPos = nPos; jt*B0'Sa
oSavedFile.seek(nPos); Q6 m.yds
} m$pRA0s2`
7<B-2g
d:_;
public synchronized int write(byte[] b,int nStart,int nLen) #@1(
{ 4HGS
int n = -1; STg} Z
try{ H5UF r,t
oSavedFile.write(b,nStart,nLen); ^/x\HGrw
n = nLen; Z^_zcH'
} ,]n~j-X
catch(IOException e) &Ll&A@yU
{ G)Y,*.,
e.printStackTrace (); uAoZ&8D6
} n:1Ijh 1
e VQ-?DK
}*qj,8-9
return n; pDvznpQ
} AA=eWg
pW>{7pXn
PQh s^D
} !<~cjgdx
%@TC- xx
P6'Se'f8
/* qTMY]=(
**SiteInfoBean.java ^7=7V0>,:
*/ '^$+G0jv
package NetFox; @^ m0>H
fd>&RbUp
P46Q3EE
public class SiteInfoBean { ?gjx7TQ?
v#X#F9C
.`v%9-5v
private String sSiteURL; //Site's URL M#m;jJqON
private String sFilePath; //Saved File's Path N0NFgW;
private String sFileName; //Saved File's Name YB2gxZ
private int nSplitter; //Count of Splited Downloading File x#R6Ez7
L2~'Z'q
T"gk^.
public SiteInfoBean() a1_o
{//nSplitter的缺省值为5 6Q_A-X3hk
//default value of nSplitter is 5 /Bh*MH
this("","","",5); R*S:/s
} $p$p C/:%
iJmzVR+
x.] tGS
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) HSAr6h
{ %:;g|PC
sSiteURL= sURL; K(d+t\ca
sFilePath = sPath; zZ<*
sFileName = sName; -%^'x&e
this.nSplitter = nSpiltter; uhp.Yv@c
MOnTp8
mo(>SnS<
} K' <[kh:cl
_5x]BH6f
3T4HX|rC
public String getSSiteURL() n&?)gKL0g
{ Dh?I
return sSiteURL; Z,Us<du
} S9r+Nsn
v_WQ<G?
U/|JAg#
public void setSSiteURL(String value) $&KkZ
{ uKvdL "
sSiteURL = value; X;l/D},.
} kLU-4W5t
DrC"M*$!
['sNk[-C
public String getSFilePath() yTZo4c"
{ cF8X
return sFilePath; Q[K)Yd
} K:~tZ
Q>rr?L`
cY kb3(
public void setSFilePath(String value) >!a- "
{ d%-/U!z?
sFilePath = value; %d(= >
} 8"ZS|^#
/wt7KL-I
\x]\W#C
public String getSFileName() PJe_qP
{ L G5_\sY!
return sFileName; .kPNWNrw
} gt02Csdt
;+6><O!G
&);P|v`8
public void setSFileName(String value) }*xjO/Ey
{ "d0=uHd5\
sFileName = value; ?# _{h
} pi/0~ke4"
-57~7 <N
9:-7.^`P
public int getNSplitter() }f?[m&<
{ E]GbLU;TH
return nSplitter; A~<!@`NjB
} UXJblo#
[wnp]'+!
#9!7-!4pW
public void setNSplitter(int nCount) : MjDcI~
{ ov;^ev,(
nSplitter = nCount; xy"'8uRi
} $/;K<*O$
} Yv@n$W`:
WQ%O/
vgD+Y
/* GQ7uxdqWBQ
**Utility.java ~?HK,`0h>
*/ Y68A+ B.
package NetFox; qIsf!1I?
6L$KMYHE
2b^Fz0 w4
public class Utility { -D'XxOI
3]mprX'
T]-MrnO
public Utility() [xr^t1
{ L/C~l3
AD?XJ3
M\{\WyeX
} e(|Z<6
-bHlFNRm
//线程睡眠 /(51\RYkir
public static void sleep(int nSecond) [X!w@d= i
{ PS+~JwDUc
try{ NLG\*mQ
Thread.sleep(nSecond); Q!V:=d
} tzIP4CR~F&
catch(Exception e) 111A e*U
{ 5:f!EMb
e.printStackTrace (); L6{gwoZf3
} F=1 #qo<?
} 1(IZ,*i
P@vUQ
//日志 L-D4>+
public static void log(String sMsg) PDuBf&/e
{ % _E?3
System.err.println(sMsg); ~o"=4q`>
} 8{2
~h;
4dPTrBQ?
public static void log(int sMsg) d9;&Y?fp
{ &|#[.ti1
System.err.println(sMsg); B#jnM~fJz
} nk%v|ZxoFv
} 52tc|j6~#
O=RS</01!
!uW*~u
/* VYkh@j
**TestMethod.java Z,E$4Z
*/ <;PKec
package NetFox; Z}uY%]
)-Hs]D:
}" vxYB!h3
public class TestMethod { Qa )+Tv
k!0O[U
g}D)MlXRq
public TestMethod() nco.j:
{ ///xx/weblogic60b2_win.exe hoqZb<:
try{ 4i)5=H
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Jp]?tlT
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); A%W]XEa<
SiteFileFetch fileFetch = new SiteFileFetch(bean); )PP yJ@M
fileFetch.start(); :QGo -,6-
} tSJ#
catch(Exception e){e.printStackTrace ();} W?.469yy
7UMZs7L$
0HoHu*+FX
} S7f.^8
e>Z&0lV:
nWIZ0Nde'
public static void main(String[] args) D`a6D
{ }]o8}$&(
new TestMethod(); Nbd4>M<
} <lf692.3
} $e7%>*?m
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