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)); TE*>a5C|
} -~rr<D\
for(int i=0;i<nEndPos.length-1;i++) &5kjjQ*HB
{ zJB+C=]D7H
nEndPos = nStartPos[i+1]; ,g<>`={kK+
} :kf3_?9rc
nEndPos[nEndPos.length-1] = nFileLength; |-SI(Khjk
} jzu l{'g
} z1}tC\9'%
4YU1Kr4
@O @|M'
//启动子线程 @&am!+z
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; aT`02X
for(int i=0;i<nStartPos.length;i++) 6Dr$*9
{ U 8qKD
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &?`d8\z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2uI`$A:
nStartPos,nEndPos,i); l(0&6ENyj
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,b2O^tJF#
fileSplitterFetch.start(); P:zEx]Y%
} 1*c0\:BQ;z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TkoCyD9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Y(Z(dV!Po
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", rRA_'t;uK
nEndPos = " + nFileLength); 2WbZ>^:Nsk
// fileSplitterFetch[nPos.length-1].start(); d-A%ZAkE]
AW{/k'%xw
`Tm8TZd66
//等待子线程结束 tyGnG0GK
//int count = 0; g,z&{pZch
//是否结束while循环 gZ79u
boolean breakWhile = false; \nWzn4f
]aL [
|Ls&~'ik
while(!bStop) 8WLh]MD`
{ ^<5^9]x
write_nPos(); ^q4:zZZ
Utility.sleep(500); j*3sjOoC
breakWhile = true; RmCn&-i
5.+$v4
aaqjE
for(int i=0;i<nStartPos.length;i++) *$WiJ3'(m
{ G`3vH,
if(!fileSplitterFetch.bDownOver) #h5Hi9LKf
{ ]i_):@
breakWhile = false; <R]Wy}2-
break; $F /p8AraK
} Z{R=h7P
} ^5zS2nm
if(breakWhile) TF([yZO'
break; :67d>wb
(cqA^.Td
RIVN>G[;L
//count++; \:f}X?:
//if(count>4) 5]2!Bb6>
// siteStop(); hc4`'r;
} K\%"RgF@&
XTn{1[.O
ogh2kht
System.err.println("文件下载结束！"); [/2@=Uh-
} 0,i+
catch(Exception e){e.printStackTrace ();} =tvm=
} ,y{fqa4
[]]LyWk
hzf}_1
//获得文件长度 5kL#V
public long getFileSize() kH(3
{ 94>7-d
int nFileLength = -1; h.+,*9T\
try{ e\bF_ N2VA
URL url = new URL(siteInfoBean.getSSiteURL()); })=c:h&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s-YV_
httpConnection.setRequestProperty("User-Agent","NetFox"); G%x,t-
Q*{H]
a1Y_0
int responseCode=httpConnection.getResponseCode(); @+Anv~B.
if(responseCode>=400) CB7R{~ $
{ ^ 8Nr%NJ
processErrorCode(responseCode); eB1eUK>
return -2; //-2 represent access is error HpgN$$\@
} !C)>
Yhv`IV-s
rq|czQ
String sHeader; oCru5F
$@ #G+QQ_
TlZlE^EE<
for(int i=1;;i++) >!ZyykAs
{ 0a;FX0S&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Y&!McM!Jw
//Utility.log(in.readLine()); P)o[p(
sHeader=httpConnection.getHeaderFieldKey(i); ~TmHnAz
if(sHeader!=null) ?wiq 3f6
{ jzOMjz~:)
if(sHeader.equals("Content-Length")) h"%,eW|^
{ YUE1 '}
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); XajY'+DIsz
break; Jv$2wH
} [>QsMUvak
} cF>;f(X
else &G5I0:a
break; ovRCF(Og,
} <k8rSxn{
} .dq.F#2B;
catch(IOException e){e.printStackTrace ();} 5<'Jd3N{&
catch(Exception e){e.printStackTrace ();} MyR\_)P?
<P)%Ms
orN2(:Ct7
Utility.log(nFileLength); FU3IK3}
#cg@Z
7!d<>_oH
return nFileLength; 6b5{
} _:z;j{@4
}&^bR)=
PYRwcJ$b\d
//保存下载信息（文件指针位置） *g_>eNpXD
private void write_nPos() dL Py%q
{ BqJrL/(
try{ zqEZ+|c=
output = new DataOutputStream(new FileOutputStream(tmpFile)); !c;p4B)
output.writeInt(nStartPos.length); {>qrf:
for(int i=0;i<nStartPos.length;i++) PyJblW
{ FH@e:-*=
// output.writeLong(nPos); D2mAyU-
output.writeLong(fileSplitterFetch.nStartPos); sg~/RSJ3
output.writeLong(fileSplitterFetch.nEndPos); J+Y|# U
} |@4hz9~3
output.close(); Kof-;T
} J'oz P^N
catch(IOException e){e.printStackTrace ();} I,q~*d
catch(Exception e){e.printStackTrace ();} TOP'Bmb
} m*WEge*$t
NomK(%8m$
,wy:RVv@e
//读取保存的下载信息（文件指针位置） ~1z8G>R
private void read_nPos() NxRiEe#m
{ 1JY90l$ME
try{ !Kn+*'#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); cF6@.)
int nCount = input.readInt(); (>% Vj
nStartPos = new long[nCount]; (?=(eo<N
nEndPos = new long[nCount]; ku8Z;ONeH
for(int i=0;i<nStartPos.length;i++) +.Ukzu~s
{ +mel0ZStS
nStartPos = input.readLong(); R}YryzV5
nEndPos = input.readLong(); m=b+V#4i(
} 206jeH9
input.close(); *^m.V=
} -CNv=vj 3
catch(IOException e){e.printStackTrace ();} S 2` ;7
catch(Exception e){e.printStackTrace ();} 7 @Qlp$[F
} CHSD8D
'Z%aBCM
= ft$j
private void processErrorCode(int nErrorCode) ;:YjgZ:+Q]
{ T{kwy3
System.err.println("Error Code : " + nErrorCode); %Y[/Ucdm
} )bJ6{&
0md{e`'q:
`o-<,
//停止文件下载 .jU0Hu{F4
public void siteStop() !,WRXE&j
{ Ji:@z%osr
bStop = true; 2{qG
for(int i=0;i<nStartPos.length;i++) )x $Vy=
fileSplitterFetch.splitterStop(); YtKX\q^.
f\_Q+!^
y(g Otg
} -Q8`p
} Rla*hc~
//负责部分文件的抓取 `t"Kq+
**FileSplitterFetch.java X'p%$HsMG
*/ [aUT #
package NetFox; ) FsSXnZL
$G.|5sEk
%}MM+1eu
import java.io.*; )O'<jwp$
import java.net.*; %5w)}|fw
yL,B\YCf8
!KW)*
public class FileSplitterFetch extends Thread { z{_Vn(Kg
T+( A7Qrx%
?=Qg
String sURL; //File URL clV/i&]Qa
long nStartPos; //File Snippet Start Position k18V4ATE]
long nEndPos; //File Snippet End Position vK/Z9wR*05
int nThreadID; //Thread's ID U5s]dUs (
boolean bDownOver = false; //Downing is over 'GT`%ck
boolean bStop = false; //Stop identical )^xmy6k
FileAccessI fileAccessI = null; //File Access interface X~b+LG/
8hV:bz"
ZPog)d@!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException tV%\Jk),
{ k}7)pJNj
this.sURL = sURL; .;Yei6H
this.nStartPos = nStart; Hc3/`.nt
this.nEndPos = nEnd; e6a8ad
nThreadID = id; ioQlC4Y
fileAccessI = new FileAccessI(sName,nStartPos);//定位 G*V 7*KC
} NsK>UJ'
At:C4>HE@
x=+H@YO\
public void run() 1z!Lk*C)
{ %8}w!2D S
while(nStartPos < nEndPos && !bStop) :RG6gvz
{ $9$NX/P
TR7TF]itb
$l0w{m!P
try{ l0)6[yXK
URL url = new URL(sURL); ZmF32Ir
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J>|`
httpConnection.setRequestProperty("User-Agent","NetFox"); 6f1Y:qK'@
String sProperty = "bytes="+nStartPos+"-"; (b5af_ c
httpConnection.setRequestProperty("RANGE",sProperty); 3_:k12%p
Utility.log(sProperty); KLB?GN?Pb
ax}Xsk_
D7wWk ,B
InputStream input = httpConnection.getInputStream(); e70*y'1fu
//logResponseHead(httpConnection); cFo-NI2
1EB`6_>y
s^< oU
byte[] b = new byte[1024]; J>&GP#7}
int nRead; 4(]('[M
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) HX^ P9jXT
{ ^4i3#}
nStartPos += fileAccessI.write(b,0,nRead); WR%iUO40
//if(nThreadID == 1) |'#NDFI>}
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M1\/ueOe
} cQb%bmBc5
3Q;l*xu
.$;GVJ-:5
Utility.log("Thread " + nThreadID + " is over!"); gE#,QOy
bDownOver = true; =0|evC
//nPos = fileAccessI.write (b,0,nRead); s6IuM )x
} *O2j<3CHf
catch(Exception e){e.printStackTrace ();} uLht;-`{n
} r6<}S(
} ,@MPzpH
%hh8\5l.:
'-qc\6UY
//打印回应的头信息 ':@qE\(
public void logResponseHead(HttpURLConnection con) UNae&Zir
{ 2sH5<5G'
for(int i=1;;i++) .`9KB3
{ Mf"B!WU>]B
String header=con.getHeaderFieldKey(i); G@2M&0'
if(header!=null) (w fZ!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =XB)sC%
Utility.log(header+" : "+con.getHeaderField(header)); ce\-oT
else I_Qnq4Sk(
break; vhW'2<(
} 1lM0pl6M
} Uyh#g^r
d29HEu
P^ VNB
public void splitterStop() b6ddXM\Z
{ 9#7zjrB
bStop = true; ~gD'up@$/
} .N2Yxty8>
7+bzCDKU
H?m2|.
} z m%\L/BF
t+tGN\q
OZD/t(4?6s
/* y{<7OTA)
**FileAccess.java O1"!'Gk[!L
*//文件访问(定位，写) ' wEP:}
package NetFox; ]n_A~Yr
import java.io.*; wl4yNC
S/|8'x{<
/uWON4
public class FileAccessI implements Serializable{ YL+W4ld
RPu-E9g@
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `:&{/|uP7
RandomAccessFile oSavedFile; YH9BJ
long nPos; '1+ Bgf
(46)v'?
bPEAG=l"-
public FileAccessI() throws IOException Fei$94a
{ ,>Q,0bVhH0
this("",0); 5sH ee,
} %9K@`v-
$uqlJG#`
7gkHKdJoMA
public FileAccessI(String sName,long nPos) throws IOException #"|Ey6&
{ _1a2Z\
oSavedFile = new RandomAccessFile(sName,"rw"); 1,E/So
this.nPos = nPos; h ? M0@Z
oSavedFile.seek(nPos); B.o&%5dG
} a)e2WgVB/E
Z,z^[Jz
ROS0Q9X
public synchronized int write(byte[] b,int nStart,int nLen) B4?P"|
{ K"D9.%7
int n = -1; >_o_&;=`v
try{ Kt-@a%O0
oSavedFile.write(b,nStart,nLen); <Aa%Uwpc
n = nLen; Je'$V%{E
} KK?}`o
catch(IOException e) ?$?Ni)Z
{ 4d#W[
e.printStackTrace (); "](~VF[J8
} o7 kGZ
g!8-yri
9}=Fdt
return n; `fH6E8N
} lyyi?/W%
p=zjJ~DVd
U*Q$:%72vO
} ^%nAx| 4xQ
IpWl;i`__
o]vdxkU]
/* <K43f#%
**SiteInfoBean.java ("{'],>
*/ ReY K5J=O
package NetFox; +$%o#~
8ViDh
~9{.!7KPc
public class SiteInfoBean { Vrnx#j-U
qnOAIP:0
0wx`y$~R
private String sSiteURL; //Site's URL 4x:fOhtP
private String sFilePath; //Saved File's Path ?h{&
private String sFileName; //Saved File's Name ;RR)C@n1
private int nSplitter; //Count of Splited Downloading File 8WAg{lVs
ykZ)`E]P`
<v\|@@X
public SiteInfoBean() *StJ5c_kg2
{//nSplitter的缺省值为5 U@9n7F
//default value of nSplitter is 5 6 R!0v8
this("","","",5); uB%`Bx'OW
} # RtrHm
PKP(:3|
q|~9%Pujg
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) EprgLZ1B
{ $+tkBM
sSiteURL= sURL; rIXAn4,dTv
sFilePath = sPath; qwN-VCj
sFileName = sName; ZY83,:<
this.nSplitter = nSpiltter; |')Z;
z2r{AQ.&
kWgxswl7H
} [j5L}e!T
:wIbKs.r
mF "ctxE
public String getSSiteURL() ;&iQNXL
{ [g<JP~4]
return sSiteURL; /vBpRm
} +Ta7b)
6%)dsTAB
!4|7U\;
public void setSSiteURL(String value) HH>]"mv
{ /@0wbA
sSiteURL = value; zgLm~
} P5[.2y_qM
>]Y`-*vw&
5RqkAC
public String getSFilePath() eOS#@6U=u
{ d8av`m
return sFilePath; Nl1&na)K}
} P!:D2zSH_
=>4,/g3
'peFT[1>(
public void setSFilePath(String value) Yk:\oM
{ 4\t9(_
sFilePath = value; =E{1QA0
} QH+Oi&xH
Pj^6.f+
a6[bF
public String getSFileName() 'y@0P5[se
{ 6%:N^B=%}
return sFileName; =YI<L8@g~
} _Nw-|N.
/KH3v!G0
syMB~g
public void setSFileName(String value) 8USF;k
{ euQd
sFileName = value; J3C"W794}
} )wmXicURC
XmLHZ,/
)abo5
public int getNSplitter() f.Jz]WXw,
{ ]@Q14
return nSplitter; JWC{"6
} !YCYmxw#
L[D}pL=
!x[+rf
public void setNSplitter(int nCount) D/rKqPp|!
{ {um~]
nSplitter = nCount; hmQD-E{Ab
} dKhDO`.s
} Y!}BmRLh2
{R\"x|
rT <=`9^{
/* c/b}39X
**Utility.java BJ1txdxvS
*/ ^,@Rd\q
package NetFox; !DXKn\aQf
D}Z].c@E
"|(+~8[
public class Utility { FSC74N/
m%ak]rv([
]QRhTz
public Utility() qpFFvZ W
{ >tYptRP
B]#0]-ua
cW%F%:b
} 0OP6VZ\
t\S}eoc
//线程睡眠 .(ki(8Z N
public static void sleep(int nSecond) l\JoWL
{ )FYz*:f>&
try{ NbSkauF~b
Thread.sleep(nSecond); X^7bOFWE
} eE+zL~CE
catch(Exception e) 4cl}ouG
{ ]&jXD=a"
e.printStackTrace (); |s+y]3-_
} C&D!TR!K
} RKx" }<#+
YOd0dKe
//日志 Yc&yv
public static void log(String sMsg) 9ssTG4Sa
{ C5$1K'X@
System.err.println(sMsg); i.C+{QH
} LY-fp+
9m/v^
p$0G EYwM
public static void log(int sMsg) (0bvd
{ amK"Z<V F
System.err.println(sMsg); TkM8GK-3
} q]DV49UK
} :D""c*
i]JD::P_H
c=0S]_
/* mR)Xq=
**TestMethod.java VE`5bD+%e
*/ Ys|tGU
package NetFox; .i) H1sD
*0^!%Y'/4
T8bk\\Od
public class TestMethod { /PafIq
ZBUEg7c
~xerZQgc
public TestMethod() Rt}H.D #
{ ///xx/weblogic60b2_win.exe zW+X5yK
try{ m0DD|7}+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); KmG*`Es
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); W1dpKv
SiteFileFetch fileFetch = new SiteFileFetch(bean); ycz6-kEp
fileFetch.start(); )"`(+Ku&c
} ph qx<N@
catch(Exception e){e.printStackTrace ();} wuRQ H]N
P-o/ax
U-&dn%Sq
} |3<tDq@+
]%>7OH'
|qnAqzK|
public static void main(String[] args) aAhXHsZ|26
{ t6(LO9Qc
new TestMethod(); .jA'BF.
} WhQK3hnm
} ^cs:S-s
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