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)); '}#9)}x!
} j*m%*_kO
for(int i=0;i<nEndPos.length-1;i++) H" 7u7l
{ FXU8[j0P_G
nEndPos = nStartPos[i+1]; W=4FFl[
} 1m0c|ckb
nEndPos[nEndPos.length-1] = nFileLength; @9|hMo
} YKf0dh;O
} 11;zNjD|
IO:G1;[/2L
B#1;r-^P<
//启动子线程 8*a&Jl
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "tpSg
for(int i=0;i<nStartPos.length;i++) P{^6v=8)
{ lqpp)Cq
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), seeBS/%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), jmW7)jT8:
nStartPos,nEndPos,i); lU8Hd|@-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ENY+^7
fileSplitterFetch.start(); #:%/(j
} FJ?IUy 6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), o2\8OxcA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 63B?.
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "" ZQ/t\
nEndPos = " + nFileLength); z*)T%p
// fileSplitterFetch[nPos.length-1].start(); m&yJzMW|
uY'HT|@:{
|$_sX9\`?|
//等待子线程结束 @U}1EC{A
//int count = 0; H} g{Cr"Ex
//是否结束while循环 |LKXOU c
boolean breakWhile = false; jWfa;&Ra
u\JNr}bL
Nda *L|
while(!bStop) _zMW=nypdx
{ xKp4*[}m
write_nPos(); m`r(p"
Utility.sleep(500); 3=ymm^
breakWhile = true; hY8reQp1
VyGJ=[ ]
N ZSSg2TX#
for(int i=0;i<nStartPos.length;i++) 0:d_Yv,D
{ .kfIi^z
if(!fileSplitterFetch.bDownOver) &@YmA1Yu)E
{ 45>?o
breakWhile = false; {Y9q[D'g.
break; ,zY$8y]
} lHX72s|V
} 8}UIbF
if(breakWhile) b|W=pSTY
break; f& '
N]sAji*
I,8Er2;)
//count++; C;urBsC
//if(count>4) uGlUc<B\*
// siteStop(); q'82qY
} HHsmLo c4
U4B(#2'
M=r)I~
System.err.println("文件下载结束！"); 5XBH$&Td
} Ph>%7M%
catch(Exception e){e.printStackTrace ();} +srGN5!
} M/K5#8Arj
JaGtsi9%.
E?0%Z&1h
//获得文件长度 | %Vh`HT
public long getFileSize() XOS[No~
{ @MCg%Afw
int nFileLength = -1; g}',(tPMZ
try{ C~iL3Cb
URL url = new URL(siteInfoBean.getSSiteURL()); 3$9W%3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HA>OkA/
httpConnection.setRequestProperty("User-Agent","NetFox"); n7-6- #
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B`J~^+`[*
int responseCode=httpConnection.getResponseCode(); TWFr 4-
if(responseCode>=400) CizX<Cr}
{ B&uz;L3
processErrorCode(responseCode); k\GcHI-
return -2; //-2 represent access is error RrQJ/ts7}
} )P|),S,;Z
"LTad`]<Ro
.0]<k,JZZ
String sHeader; "a U aotx
Y/zj[>
QMbOuw
for(int i=1;;i++) ~M4;
{ ,nDaqQ-C!!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); yaH Zt`Y
//Utility.log(in.readLine()); O@C@eW#
sHeader=httpConnection.getHeaderFieldKey(i); E=!\z%4
if(sHeader!=null) .OY`Z)SS%
{ @6T/Tdz
if(sHeader.equals("Content-Length")) ikiypWq
{ >V}#[/n
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); v^ VitLC
break; :G%61x&=Zc
} $ gS>FJ
} }Kbb4]t|"
else E09:E
break; v z '&%(
} | h#u^v3
} W|63Ir67
catch(IOException e){e.printStackTrace ();} 7E~;xn;
catch(Exception e){e.printStackTrace ();} fS78>*K
IB]l1<
j+ 0I-p
Utility.log(nFileLength); VS8Rx.?
^,T(mKS
}?Ai87-{
return nFileLength; j HJ`,#
} L0WN\|D
j\^CV?}sm'
a HR"n|7{
//保存下载信息（文件指针位置） y/ef>ZZ
private void write_nPos() RdRp.pb8
{ l]l'4@1
try{ YGCL2Y
output = new DataOutputStream(new FileOutputStream(tmpFile)); GDiBl*D
output.writeInt(nStartPos.length); _^%,x
for(int i=0;i<nStartPos.length;i++) (M.&^w;`,
{ ^sLdAC
// output.writeLong(nPos); Cd}<a?m,
output.writeLong(fileSplitterFetch.nStartPos); 68WO~*
output.writeLong(fileSplitterFetch.nEndPos); \n|EM@=eE
} lchPpm9
output.close(); m`^q <sj
} cB}D^O
catch(IOException e){e.printStackTrace ();} Vb]=B~^`
catch(Exception e){e.printStackTrace ();} x)O!["'"
} %2V?,zY@
K^<BW(s
+}os&[S
//读取保存的下载信息（文件指针位置） Q:d]imw!O
private void read_nPos() 0[?Xxk}s0
{ ?QdWrE_
try{ 1ztG;\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); u^8{Z;mm
int nCount = input.readInt(); _TQj~W<
nStartPos = new long[nCount]; :emiQ
nEndPos = new long[nCount]; Tqn@P
for(int i=0;i<nStartPos.length;i++) 5f K_Aq{
{ nazZ*lC
nStartPos = input.readLong(); y,,dCca
nEndPos = input.readLong(); -ifFbT+x
} 4yA+h2
input.close(); 6) [H?Q
} XrGglBIV
catch(IOException e){e.printStackTrace ();} V#gK$uv
catch(Exception e){e.printStackTrace ();} C7ScS"~
} HJ[cM6$2
uo%)1NS!
#yF&X(%
private void processErrorCode(int nErrorCode) 1JG'%8}#8
{ L2i_X@/
System.err.println("Error Code : " + nErrorCode); O^duZ*b
} e)? .r9pA;
=|y9UlsD
IDriGZZ<)6
//停止文件下载 h_,i&d@(
public void siteStop() j@3Q;F0ba
{ (m(JK^
bStop = true; bI9~jWgGp
for(int i=0;i<nStartPos.length;i++) ~H<6gN<j(.
fileSplitterFetch.splitterStop(); ^7WN{0
kxIF#/8
aP@N)"
} [uN? ~lp\%
} 2*l/3VW
//负责部分文件的抓取 T<Z &kYU:R
**FileSplitterFetch.java W/bQd)Jvk
*/ :zke %Yx
package NetFox; i^Y+?Sx
CXx*_@}MU
Ed df2;-.
import java.io.*; ?(F6#"/E
import java.net.*; <7Or{:Sc90
goOCu
dhf!o0'1M
public class FileSplitterFetch extends Thread { u5b|#&-mX
`w7v*h|P
Ma']?Rb`
String sURL; //File URL S3*`jF>q
long nStartPos; //File Snippet Start Position Hc$O{]sq
long nEndPos; //File Snippet End Position a;qryUyG
int nThreadID; //Thread's ID bP$dU,@p~
boolean bDownOver = false; //Downing is over e>7>j@(K]
boolean bStop = false; //Stop identical SaAFz&WRl
FileAccessI fileAccessI = null; //File Access interface Q}K"24`=
3-qr)h
b)5uf'?-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Ru!iR#s)!
{ BWv^zi
this.sURL = sURL; S8wLmd>
this.nStartPos = nStart; IT7wT+
this.nEndPos = nEnd; $)ijN^hV
nThreadID = id; :tB1D@Cb6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 c&?m>2^6
} Sc1 8dC0
p\tm:QWD;
03qQ'pq
public void run() rIu$pZO
{ Ls$D$/:q?
while(nStartPos < nEndPos && !bStop) _~J {wM
{ D4lG[qb
0oZ= yh
O1U=X:Zl
try{ I7vz+>Jr
URL url = new URL(sURL); ):68%,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vzs)[AD
httpConnection.setRequestProperty("User-Agent","NetFox"); 8f)?{AX0
String sProperty = "bytes="+nStartPos+"-"; Fg5kX
httpConnection.setRequestProperty("RANGE",sProperty); 0$)>D==
Utility.log(sProperty); BxWPC#5
vkx7paY_
JHM9
InputStream input = httpConnection.getInputStream(); 'qb E=
//logResponseHead(httpConnection); L:pYn_
qYjce]c
2W96Zju\
byte[] b = new byte[1024]; vrhT<+q
int nRead; +_?hK{Ib"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8:c-k|CX
{ t?x<g<PJ4
nStartPos += fileAccessI.write(b,0,nRead); ,c$_t+
//if(nThreadID == 1) j_!F*yul
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jrlVvzZ
} 9N%We|L,c
XSe=sHEI
0d"[l@UU0
Utility.log("Thread " + nThreadID + " is over!"); 7$vYo _
bDownOver = true; a LroD$#
//nPos = fileAccessI.write (b,0,nRead); Ustv{:7v
} <ro7vPKNa
catch(Exception e){e.printStackTrace ();} uk<4+x,2)
} hk(ZM#Bh
} <EB+1GFuI
B:;pvW]
@fZ,.2ar
//打印回应的头信息 |mdVdD~go
public void logResponseHead(HttpURLConnection con) ( iBl
{ G C),N\@Q
for(int i=1;;i++) <CYd+! (
{ j^j1
String header=con.getHeaderFieldKey(i); \:# L)
if(header!=null) qPX~@^`9
//responseHeaders.put(header,httpConnection.getHeaderField(header)); fo*2:?K&
Utility.log(header+" : "+con.getHeaderField(header)); H1pO!>M
else =)H.cuc
break; cz#rb*b
} 6y%qVx#!
} c)TPM/>(p
#zv3b[@
"/*\1v9
public void splitterStop() N ,'GN[s
{ %Q__!D[
bStop = true; {7"Q\
} d6?j`~[7#-
]_mb7X>
f}#~-.NGs
} $<dH?%!7
$Uq|w[LA
ld|5TN1
/* G6q }o)[m)
**FileAccess.java fnjPSts0
*//文件访问(定位，写) F 5bj=mI
package NetFox; <Dl*l{zba
import java.io.*; V%7WUq
knu,"<
#l\=}#\1Wb
public class FileAccessI implements Serializable{ =t#llgi~
~9a<0Mc?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 I+%[d^,
RandomAccessFile oSavedFile; iTBx\u%{
long nPos; &=@IzmA
'Vzp2
sQUM~HD\a
public FileAccessI() throws IOException 4x=v?g&
{ >\-hO&%_
this("",0); :KSV4>X[%a
} .;y.]Z/;
Z, zWuE3
#vz7y(v
public FileAccessI(String sName,long nPos) throws IOException Q04al=
{ e8>})
oSavedFile = new RandomAccessFile(sName,"rw"); qTRsZz@
this.nPos = nPos; lLX4Gq1
oSavedFile.seek(nPos); =57>!)
} oA7tEu
n$MO4s8)
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public synchronized int write(byte[] b,int nStart,int nLen) lK?uXr7^
{ LiC*@W
int n = -1; YiXk5B0Uh
try{ 2RVN\?s:
oSavedFile.write(b,nStart,nLen); 7X`g,b!
n = nLen; 0#7>o^2
} n*R])=F@c
catch(IOException e) g+8OekzB5
{ /QK6Rac-
e.printStackTrace (); "(3[+W{|
} Q,,e+exbb5
I13y6= d
bQzZy5,
return n; j2t7'bO_
} e@L=LW>
@+&LYy72
x77*c._3v
} DzAg"6=CS
yJ[0WY8<kC
QGMV}y
/* <O(4TO
**SiteInfoBean.java e[{0)y>=
*/ uP`Z12&
package NetFox; $g^@AdE%
]}>2D,;
-vAC"8)S
public class SiteInfoBean { AmUr.ofu
rX U
[$ubNk;!z
private String sSiteURL; //Site's URL lB8-Z ow
private String sFilePath; //Saved File's Path @f_Lp%K
private String sFileName; //Saved File's Name I }a`0Y&{
private int nSplitter; //Count of Splited Downloading File ")1:F>
DHg:8%3x
WJ]T\DI
public SiteInfoBean() *[Imn\hu
{//nSplitter的缺省值为5 `Y0%cXi3
//default value of nSplitter is 5 R)?*N@.s
this("","","",5); ,5P0S0*{
} [CTnXb
'9%\;
k`cfG\;r
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^L,K& Jd
{ =bAx,,D#
sSiteURL= sURL; ]"pVj6O
sFilePath = sPath; +X\FBvP&
sFileName = sName; dUD[e,?
this.nSplitter = nSpiltter; vJLK,[
s2a{>II6
{Ea b j
} xf'V{9*
5p,RI&nlN
W Tcw4
public String getSSiteURL() ;_XFo&@
{ K,tQ!kk
return sSiteURL; ;gD})@
} %6t:(z
./XYd"p
Ml`:UrU
public void setSSiteURL(String value) ;'gWu
{ cQjv$$&6[
sSiteURL = value; 9V a}I-
} '"52uZ{
^23~ZHu
m%0p\Y-/
public String getSFilePath() 2zX]\s?3
{ B4ZBq%Z_
return sFilePath; ynp8rf
} YByLoM*
a6ekG YW
}czrj%6
public void setSFilePath(String value) l&[O
{ gZVc 5u<
sFilePath = value; &L3M]
} 2V]UJ<
#j;^\rSv-
&Hrj3E
public String getSFileName() g/4[N{Xf
{ T%+#xl
return sFileName; \-E^lIVF
} ??5Q)Erm1
pG_;$8Hc
7o\@>rNWP
public void setSFileName(String value) y4yhF8E>;U
{ ^"E^zHM(
sFileName = value; UB@Rs|)
} ip\sXVR
z>xmRs
rDtY[
public int getNSplitter() K&u_R
{ 1pVS&0W
return nSplitter; .C%<P"=J4h
} *9 {PEx
b\f O8{k
#x@$lc=k3
public void setNSplitter(int nCount) Nd4f^Y
{ ]dVGUG8
nSplitter = nCount; 4>YR{
} ]U?^hZ_
} <(#(hDwy
0J*??g-n
*YI98
/* yHYsZ,GE
**Utility.java #Bze,?@
*/ I]|Pq
package NetFox; oE@a'*.\
3l]lwV
hXw]K"
public class Utility { AhN4mc@
_1X!EH"
BX/8O<s0
public Utility() ?JbilK}a
{ yNBQGSH
alJ)^OSIe
m~BAyk^jo3
} s3N'02G
fy1|$d{'
//线程睡眠 Mc lkEfn
public static void sleep(int nSecond) ]2A^1Del
{ ;7*[Bcj.
try{ + /G2fhE
Thread.sleep(nSecond); 6{K,c@VFd
} @)F)S7
catch(Exception e) eSn+B;
{ 1y&\5kB
e.printStackTrace (); @3i\%R)n;
} bG"~"ipn%
} +.8 \p5
>tS'Q`R
//日志 d7^}tM
public static void log(String sMsg) b#c:u2
{ &N9 a<w8+
System.err.println(sMsg); Yu/ID!`Z
} krxo"WgD
OG~gFZr)6
u2I*-K
public static void log(int sMsg) r+!YIk
{ \<h0Q,e
System.err.println(sMsg); -/B+T>[nTb
} Z3e| UAif
} /V8#[9K
yqs4[C
,oe <
/* u]wZQl#-
**TestMethod.java .8g)av+
*/ ~%F9%=
package NetFox; 8$cLG*=h4
CZe ]kXNv
.~db4d]
public class TestMethod { KM0ru
L<S9
wo}H'Q}Hj
public TestMethod() }v;V=%N+v
{ ///xx/weblogic60b2_win.exe ~Gp[_ %K
try{ .<?GS{6 N
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); CT@ jZtg0
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8,Z_{R#|
SiteFileFetch fileFetch = new SiteFileFetch(bean); Tb}4wLu
fileFetch.start(); Rh2+=N<X
} OKZV{Gja
catch(Exception e){e.printStackTrace ();} 234p9A@
o 11jca|
Xq4O@V
} `RT>}_j
iXkF1r]i
&AMl:@p9
public static void main(String[] args) urc| D0n
{ ^0)g/`H^>
new TestMethod(); G't$Qx,IC
} f)rq%N &
} o|^3J{3G
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