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)); {EOn r1
} aZI>x^X
for(int i=0;i<nEndPos.length-1;i++) v>rqOI
{ &1*4%N@'
nEndPos = nStartPos[i+1]; 'uPxEu4 >4
} 4,j4E@?pG9
nEndPos[nEndPos.length-1] = nFileLength; '&N: S-
} 4\&H?:c.
} w}IL 8L(D
M_qP!+Y
w/qQ(]n8
//启动子线程 $/NGNkl[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; v;K{|zUdB
for(int i=0;i<nStartPos.length;i++) J f\Qf
{ 9+]ZH.(YE
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qRgK_/[]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), pZc9q8j3
nStartPos,nEndPos,i); !8wZw68"
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D9}d]9]$
fileSplitterFetch.start(); uOyLC<I/
} bq c;.4$
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), JOA%Y;`<#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); CHQ{+?#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", t9-_a5>E\}
nEndPos = " + nFileLength); {fAh@:{@
// fileSplitterFetch[nPos.length-1].start(); c80 }1
F?}m8ZRv
*raIV]W3
//等待子线程结束 |M[v493\
//int count = 0; 6b-
//是否结束while循环 M3hy5j(b
boolean breakWhile = false; Nb#H@zm
^AovkK(p
{.s]\C
while(!bStop) ,2=UuW"K
{ 2N6Pa(6
write_nPos(); <ol$-1l#9
Utility.sleep(500); 0!3!?E <
breakWhile = true; -=-x>(pRW7
e1f^:C
H @3$1h&YS
for(int i=0;i<nStartPos.length;i++) ,gAr|x7_
{ sW>P-
if(!fileSplitterFetch.bDownOver) D6C-x
{ o'x_g^ Y
breakWhile = false; K9x*Sep
break; w3>Y7vxiz`
} b&hF')_UOz
} [8V(N2
if(breakWhile) `^s]?
break; Y\Fuj)
kMwIuy
6E*Zj1KX
//count++; (P]^8qc
//if(count>4) Ymrpf
// siteStop(); ZI#SYEF6
} 0C9QAJa
ve64-D
EkfGw/WDw
System.err.println("文件下载结束！"); ;-<<1Jz/2
} <.y^
catch(Exception e){e.printStackTrace ();} o'= [<
} '|dKg"Yl
ey9fbS ^I
e>)}_b
//获得文件长度 R'1vjDuv
public long getFileSize() H|(*$!~e
{ X*p:&=o
int nFileLength = -1; IdC k
try{ |Ls&~'ik
URL url = new URL(siteInfoBean.getSSiteURL()); -Z\UYt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); '3Lx!pMhN
httpConnection.setRequestProperty("User-Agent","NetFox"); YA8yMh*4D?
5.+$v4
x""Mxn]gD
int responseCode=httpConnection.getResponseCode(); ?tal/uC
if(responseCode>=400) q4IjCu+
{ 6|(7G64{
processErrorCode(responseCode); j:vD9sdQ
return -2; //-2 represent access is error `5~o=g
} H'0J1\ h
ggYIq*4
w~FO:/
String sHeader; XN0RT>@
A=2nj
ogh2kht
for(int i=1;;i++) BYA=M*f
{ Y9(i}uTi
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5G]#'tu
//Utility.log(in.readLine()); COl%P
sHeader=httpConnection.getHeaderFieldKey(i); \)6?u_(u
if(sHeader!=null) *b7 ^s,?
{ ^_#gIT\
if(sHeader.equals("Content-Length")) _o=`-iy9
{ jWb\"0)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); daokiU+l2
break; $K>d\{@+7
} \Jj'60L^
} ^ 8Nr%NJ
else u BW
break; 7E84@V[\
} !nD[hI8P
} mm9S#Ya
catch(IOException e){e.printStackTrace ();} 5;KT-(q~
catch(Exception e){e.printStackTrace ();} @5nkI$>3z
y`P7LC
E4fvYV_ra
Utility.log(nFileLength); Yv`1ySR
qm&53
AXv3jH,HF
return nFileLength; f>JzG,-
} {&AT}7
=P+wp{?AN|
&cv/q$W4
//保存下载信息（文件指针位置） :$@zX]?M
private void write_nPos() L bK1CGyA
{ TbUkqABm
try{ 9~ .BH;ku
output = new DataOutputStream(new FileOutputStream(tmpFile)); WlJRKM2
output.writeInt(nStartPos.length); |r*1.V(
for(int i=0;i<nStartPos.length;i++) #T#FUI1p
{ }t{^*(
// output.writeLong(nPos); IaZAP
output.writeLong(fileSplitterFetch.nStartPos); G37L 9IG-M
output.writeLong(fileSplitterFetch.nEndPos); p<.!::*%(
} k/f_@8
output.close(); 78}%{7YY
} 63\>MQcLy
catch(IOException e){e.printStackTrace ();} Y-9j2.{
catch(Exception e){e.printStackTrace ();} y"n~ET}e7
} 3uiitjA]
(#>5j7i8#
mi3q1npb7[
//读取保存的下载信息（文件指针位置） -^%"w
private void read_nPos() u(Q(UuI
{ (?=(eo<N
try{ p~y 4q4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +.Ukzu~s
int nCount = input.readInt(); 0R{R=r]
nStartPos = new long[nCount]; LA(JA
nEndPos = new long[nCount]; JQv ZTwSI
for(int i=0;i<nStartPos.length;i++) W`rE\P
{ YmF(o
nStartPos = input.readLong(); 7 @Qlp$[F
nEndPos = input.readLong(); cnO4NUDv
} w4/)r-Z4I
input.close(); x{w?X.Nt
} DWO:
catch(IOException e){e.printStackTrace ();} `o-<,
catch(Exception e){e.printStackTrace ();} w9}IM149
} o=5uM
z?g4^0e
)x $Vy=
private void processErrorCode(int nErrorCode) */qc%!YV9
{ ijSYQ
System.err.println("Error Code : " + nErrorCode); ))zaL2UP.
} Z@Z`8M@Q,
~DS9{Y
~H."{
//停止文件下载 h(K4AiGE
public void siteStop() (8/xSOZ[
{ p5w g+K
bStop = true; T+( A7Qrx%
for(int i=0;i<nStartPos.length;i++) +OP'/
fileSplitterFetch.splitterStop(); :jCaDhK
,)m-nZ5
f4^_FK&
} y$W3\`2q
} ,o6: V]a
//负责部分文件的抓取 tV%\Jk),
**FileSplitterFetch.java e;\c=J,eE
*/ 1EzA@3:{
package NetFox; 7guxkN#
7]53GGNO
;f*xOdi*k
import java.io.*; 1@Gv`{v
import java.net.*; x=+H@YO\
`84yGXLK
[#H8Mb+7
public class FileSplitterFetch extends Thread { Z k_&Kw|
o?\Pw9Y
X:bgY
String sURL; //File URL )]Rr:i9n
long nStartPos; //File Snippet Start Position I>|?B(F
long nEndPos; //File Snippet End Position KLB?GN?Pb
int nThreadID; //Thread's ID jR:Fih-}
boolean bDownOver = false; //Downing is over (.)s =
boolean bStop = false; //Stop identical 1EB`6_>y
FileAccessI fileAccessI = null; //File Access interface Wb$bCR#?<
"=O)2}
6jA Q
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException m\Nc}P_"p
{ rZ7 Ihof
this.sURL = sURL; ^|z>NV5>
this.nStartPos = nStart; efm<bJB2
this.nEndPos = nEnd; $'wl{D"
nThreadID = id; S6I8zk)Z4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 uLht;-`{n
} qlP=Y .H
%hh8\5l.:
0SYkDI
public void run() h[?28q$
{ +g&W423k_
while(nStartPos < nEndPos && !bStop) j=LF1dG"
{ n9yxZu
.Dz /MSl
;DpK*A
try{ vhW'2<(
URL url = new URL(sURL); D\JYa@*?.h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _BV:i:z
httpConnection.setRequestProperty("User-Agent","NetFox"); *bK@A2`
String sProperty = "bytes="+nStartPos+"-"; u""=9>0
httpConnection.setRequestProperty("RANGE",sProperty); ZVL0S{V-mh
Utility.log(sProperty); WfVie6
J\BdC];
7Fx8&Z
InputStream input = httpConnection.getInputStream(); '}=M~
//logResponseHead(httpConnection); W*2SlS7
K.SHY!U}
n1|%xQBU@
byte[] b = new byte[1024]; ]Yy Sf
int nRead; N C&1l]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Fk\xq`3'c
{ "Q( 8FF
nStartPos += fileAccessI.write(b,0,nRead); (46)v'?
//if(nThreadID == 1) 9azPUf) C
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,>Q,0bVhH0
} s]qfLC
ScD9Ct*):C
#"|Ey6&
Utility.log("Thread " + nThreadID + " is over!"); ME.LS2'n
bDownOver = true; ,3K?=e2
//nPos = fileAccessI.write (b,0,nRead); AMr9rBd
} sgX~4W"J
catch(Exception e){e.printStackTrace ();} N78Ev7PN
} C^a~)r.h
} Kt-@a%O0
$FoNEr&q
8`D_"3j3g\
//打印回应的头信息 @'QBrE
public void logResponseHead(HttpURLConnection con) 9M6&+1XE
{ Pz?O_@Ln
for(int i=1;;i++) `fH6E8N
{ lxeolDl
String header=con.getHeaderFieldKey(i); 1DX=\BWp
if(header!=null) IpWl;i`__
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >y?$aJ8ZV
Utility.log(header+" : "+con.getHeaderField(header)); pJmn;XbME
else <(v!Xj^yO
break; @!S5FOXipZ
} ,T]okN5uI
} Dbgw)n*2
TCVJ[LbJ
YRK4l\_`
public void splitterStop() b@7 ItzD
{ M*x_1h5n
bStop = true; X/Ae-1!
} .e6:/x~p*
&0 @2JS/!
Zffzyh
} ]8RcZn
j,~h:MT
}{[F+|\>,e
/* oOuWgr]0
**FileAccess.java *_ "j"{
*//文件访问(定位，写) /t816,i
package NetFox; [j5L}e!T
import java.io.*; v8LKv`I's
G,J$lTX
hp)3@&T
public class FileAccessI implements Serializable{ 4h-y'&Z
rwU[dqBRhc
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 P5[.2y_qM
RandomAccessFile oSavedFile; 2 Y%$6NX
long nPos; <h(tW
I&4|T<j
myH#.$=A
public FileAccessI() throws IOException }v`5
{ ,<%],-Lt[
this("",0); 90Q}9T\
} QH+Oi&xH
.Zo8KwkFY
ibEQ52
public FileAccessI(String sName,long nPos) throws IOException |Kb-oM&^#
{ /KH3v!G0
oSavedFile = new RandomAccessFile(sName,"rw"); R`Q9|yF\
this.nPos = nPos; Qd$d*mwg:
oSavedFile.seek(nPos); 3rs=EMz:w
} x#U?~6.6
oveW)~4
w J; y4
public synchronized int write(byte[] b,int nStart,int nLen) 68d(6?OgW
{ TTS}, `
int n = -1; jytfGE:
try{ 9^XT,2Wwf
oSavedFile.write(b,nStart,nLen); hmQD-E{Ab
n = nLen; [@Y?'={qE
} $kg!XT{V
catch(IOException e) bq]af.o*
{ VDBP]LRF
e.printStackTrace (); jrG@ +" }
} dYW19$W n
FSC74N/
Vc}m_T]O
return n; [26"?};"%
} 7\<#z|
cW%F%:b
J1hc :I<;
} M{1't
^I@43Jy/
)FYz*:f>&
/* (Jy7
**SiteInfoBean.java [*Wq6n
*/ *ix&"|h
package NetFox; `#E1FB2M
==~X8k|{E
{a\m0Bw/
public class SiteInfoBean { 9ssTG4Sa
5F18/:\n
i.C+{QH
private String sSiteURL; //Site's URL !SMIb(~[z
private String sFilePath; //Saved File's Path 9m/v^
private String sFileName; //Saved File's Name @/g%l1$`
private int nSplitter; //Count of Splited Downloading File ML9ZS @
q]DV49UK
jA?A)YNQb
public SiteInfoBean() =]K;"
{//nSplitter的缺省值为5 Ivmiz{Oii
//default value of nSplitter is 5 hQv~C4Wfrf
this("","","",5); @2nar<
} qH1[BsOx
9@9(zUS|
.Ks%ar
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) bH%k)
{ _ fJ5z
sSiteURL= sURL; n6Je5fE
sFilePath = sPath; -~n^?0
sFileName = sName; &`Oj<UyJY
this.nSplitter = nSpiltter; >hHjDYjbf
*](maF~%C
mnh>gl!l
} roSdcQTeT
gi\2bzWkbX
P/6$T2k_
public String getSSiteURL() [#hpWNez(>
{ -.<fGhmU
return sSiteURL; 6O"?wN%$
} @TBcVHy
-FftEeo7
<#/r.}.x
public void setSSiteURL(String value) O<[h
{ &\),V1"
sSiteURL = value; =;Ap+}
} Mm7;'Zbg
<cS"oBh&u0
3>asl54
public String getSFilePath() HEh,Cf7`'
{ r*_z<^d
return sFilePath; Sp/t[\,'
} }.*"ezaZw
F/O5Z?C?
ggn C #$
public void setSFilePath(String value) f4[fXP;A
{ -7-r~zmr
sFilePath = value; q9+`pj
} >2vUFq`H
I "Qf};n
$[(amj-;l
public String getSFileName() +\Uq=@
{ .kwz$b+h
return sFileName; Hreu3N
} 6="Qwrk
[Ey[A|g
n0)0"S|y1
public void setSFileName(String value) ]cQYSN7!SY
{ G42J
sFileName = value; _L8|ZV./
} +|0f7RB+R
KYw~(+gHv2
n<,:;0{
public int getNSplitter() U~3uu&/r
{ fl@=h[g#t
return nSplitter; ,i]X^z5!
} fI<|]c}P&J
[d dKC)tA
o,NTIh
public void setNSplitter(int nCount) xxy (#j$
{ 3[{RH*nHD
nSplitter = nCount; ;bYS#Bid{V
} vQH6CB"
} wn1` 9
t/$:g9V%FA
ioW&0?,Ym
/* I@/s&$H`l
**Utility.java f[ 'uka.U
*/ Ot<vn34mt:
package NetFox; <Jc :a?ICe
?zpN09e
V|\dnVQ'-%
public class Utility { E\Qm09Dj`<
_8 C:Md`
H@uDP
public Utility() $-w&<U$E
{ aam6R/4
1CmjEAv%/
P:OI]x4
} t,]E5,1
QKHAN{hJ
//线程睡眠 zz m[sX}
public static void sleep(int nSecond) `b:yW.#w3l
{ Y=5}u&\
try{ b+#A=Z+Pr
Thread.sleep(nSecond); Vi*HG &DD
} 59MpHkr
catch(Exception e) qdNt2SO
{ Vh}F#~BrI
e.printStackTrace (); %AJTU3=0
} o+0x1Ct3P
} JwNB)e D
Yw6^(g8
//日志 oMeIXb)z
public static void log(String sMsg) $6DA<v^=z
{ FoKAF &h7
System.err.println(sMsg); MJ_]N+
} b[Qe} `W
xT8pwTO
%8c2d
public static void log(int sMsg) ,!>1A;~wT
{ jU2vnGw_
System.err.println(sMsg); _O;2.M%@
} Wz+7CRpeP
} WlHK
lS96sjJp@
= P@j*ix
/* 6F:<c
**TestMethod.java hM "6-60
*/ RlUX][)
package NetFox; $d\>^Q
E(-@F%Q
UAEu.AT
public class TestMethod { Hw1:zro
]9PQKC2&
|w+N(wcJ
public TestMethod() ',bSJ4)Y
{ ///xx/weblogic60b2_win.exe ?F"mZu
try{ <HB@j}qi
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); l|j}Ggen
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); jBMGm"NE
SiteFileFetch fileFetch = new SiteFileFetch(bean); <5E: ,<
fileFetch.start(); Nv5)A=6#AA
} g>pvcf(
catch(Exception e){e.printStackTrace ();} eufGU)M
9$*O^
6%a:^f]
} GV0-"9uwX~
>e"vPW*[
.K`EflN
public static void main(String[] args) lPZYd8
{ %$[#/H7=W
new TestMethod(); -*[:3%
} \e9rXh%
} A-f,&TO
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