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)); R@t?!`f!+
} UO8#8
for(int i=0;i<nEndPos.length-1;i++) Z2`(UbG}
{ e4Ol:V
nEndPos = nStartPos[i+1]; u*Eb4
} /r Zj=
nEndPos[nEndPos.length-1] = nFileLength; "YHqls}c
} 31k.{dnm
} h9LA&!
%v:9_nwO)
|"DQ^)3Pi
//启动子线程 Q u2W
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 21M@z(q*
for(int i=0;i<nStartPos.length;i++) /og2+!
{ l,HMm|oU
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ra[{K@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), em<(wJ-Y
nStartPos,nEndPos,i); HS]|s':
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "zR+}
fileSplitterFetch.start(); f$9V_j-K+
} ?%(8RQ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q/r9r*>z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); He. gl
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "CBe$b4
nEndPos = " + nFileLength); Z.<OtsQN
// fileSplitterFetch[nPos.length-1].start(); t.c XrX`k
zS18Kl
j*<H18^G
//等待子线程结束 v7T05
//int count = 0; #rqLuqw
//是否结束while循环 E"&fT!yi
boolean breakWhile = false; !6\{q M
#-1 ;
N|?"=4Z?
while(!bStop) B@G'6 ?
{ bcC;i~9
write_nPos(); `gfh]7T
Utility.sleep(500); #, W7N_mt
breakWhile = true; 0Pu$1Fp
3D[IZ^%VtM
`omZ'n)
for(int i=0;i<nStartPos.length;i++) 8v\BW^z3
{ xRq|W4ay
if(!fileSplitterFetch.bDownOver) `] ;*k2
{ N^xnx<
breakWhile = false; ])egke\!
break; o X )r4H?
} ?@6N EfQf
} QNJ )HNLp
if(breakWhile) _CDUUr
break; ]6Kx0mW
+rfw)c'
a,x-akZWf
//count++; F]@vmzr
//if(count>4) :w:hqe|_
// siteStop(); w4<1*u@${
} j8WnXp_
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(eS4$$g
System.err.println("文件下载结束！"); 3|8\,fO?
} Z\D!'FX
catch(Exception e){e.printStackTrace ();} LJ`*&J
} R2yiExw<
CEq0ZL-W
Tn< <i
//获得文件长度 uV`r_P
public long getFileSize() m!SxX&m"G
{ v#{Sx>lO
int nFileLength = -1; C:xgM'~+
try{ lt`(R*B%
URL url = new URL(siteInfoBean.getSSiteURL()); ({i}EC7{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); QI'ule
httpConnection.setRequestProperty("User-Agent","NetFox"); t J N;WK.6
/]=Ih
aFGEHZJQ
int responseCode=httpConnection.getResponseCode(); s'qd%JxD
if(responseCode>=400) zs:OHEZw
{ :{bvCos<)
processErrorCode(responseCode); #mLF6"A
return -2; //-2 represent access is error u6Fm qK]Dj
} Pky/fF7e
b^_#f:_j
A^nB!veh
String sHeader; SB0Cq
=7wI/5iN
CtJ*:wF
for(int i=1;;i++) F=!p7msRB
{ luRtuXn[8
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 0+%{1JkJq
//Utility.log(in.readLine()); q">lP(t
sHeader=httpConnection.getHeaderFieldKey(i); *UhYX)J
if(sHeader!=null) F9p'|-
{ s9+Rq*Qd
if(sHeader.equals("Content-Length")) 4<[,"<G~3
{ ?-%Q[W
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); L|pMq!@J
break; 5&Al
} N^z4I,GV(
} kN_ i0~y@-
else 8Yc'4v#}
break; z)p( l!
} ui%B|b&&
} rT7W_[&P
catch(IOException e){e.printStackTrace ();} WyciIO1
catch(Exception e){e.printStackTrace ();} IA I!a1e!
`,a6su (?
U27YH1OK
Utility.log(nFileLength); KtTv0[66
&0cfTb)dG
;]!QLO.bs^
return nFileLength; Ro3C(aRx
} l\g>@b
G(gJtl
m_YXTwwx
//保存下载信息（文件指针位置） ~SUrbRaY>
private void write_nPos() z#9Tg"8]
{ }zC9;R(E
try{ d1]CN6 7{G
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3+vbA;R
output.writeInt(nStartPos.length); N$]B$vv
for(int i=0;i<nStartPos.length;i++) ,yc_r=_
{ eA q/[(
// output.writeLong(nPos); xe?!UCUb@
output.writeLong(fileSplitterFetch.nStartPos); Rr#Zcs!G
output.writeLong(fileSplitterFetch.nEndPos); ZD!?mR+-
} q_iPWmf p*
output.close(); <8;SSdoKi
} !2L?8oP-z
catch(IOException e){e.printStackTrace ();} N~NUBEKcp
catch(Exception e){e.printStackTrace ();} 9#(Nd, m})
} *{WhUHZF
SFqY*:svOw
8R|!$P
//读取保存的下载信息（文件指针位置） @cYb37)q=
private void read_nPos() W D8
{ j=|cx+nb
try{ MXQua:&HW
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); wNc.z*+O"H
int nCount = input.readInt(); xs#g
nStartPos = new long[nCount]; >,%or cN
nEndPos = new long[nCount]; #<h//<
for(int i=0;i<nStartPos.length;i++) +}3l$L'bY
{ u7||]|2
nStartPos = input.readLong(); PY81MTv0;
nEndPos = input.readLong(); (|O9L s7N
} %M)LC>c
input.close(); rnAQwm-8O%
} RW"QUT
catch(IOException e){e.printStackTrace ();} vq?Lej
catch(Exception e){e.printStackTrace ();} 4# +i\H`
} WSEw:pln
hK]mnA[Y
)?`G"(y
private void processErrorCode(int nErrorCode) Y#e,NN
{ LH}]& >F
System.err.println("Error Code : " + nErrorCode); :/A7Z<u,
} W*2d!/;7>
#hMS?F|
6LRvl6ik
//停止文件下载 SG$V%z"e
public void siteStop() m3T=x =
{ _c!$K#Yl{
bStop = true; xP{)+$n
for(int i=0;i<nStartPos.length;i++) t;HM
fileSplitterFetch.splitterStop(); sdp3geBYo
#jj+/>ZOi
`;j@v8n$*
} HQkK8'\LP
} nh XVc((
//负责部分文件的抓取 7q%xF#mK=
**FileSplitterFetch.java ^sVr#T
*/ 52,[dP,g
package NetFox; Am ~P$dN
B,S~Idr}
gwGw
import java.io.*; &9Kni/
import java.net.*; -UB XWl
;cEoc(<?
;F_pF+&q
public class FileSplitterFetch extends Thread { =\`iC6xP}
%6.WGuO
Z".Xroq~
String sURL; //File URL U9"(jl/o
long nStartPos; //File Snippet Start Position v<3KxP'a
long nEndPos; //File Snippet End Position Y_zMj`HE
int nThreadID; //Thread's ID xovsh\s
boolean bDownOver = false; //Downing is over c/DK31K
boolean bStop = false; //Stop identical O!G!Gq&
FileAccessI fileAccessI = null; //File Access interface zm!M'|~@7
4`e[gvh
q6'Q-e)
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException lrjVD(R=g
{ :%-w/QwTR
this.sURL = sURL; ~pT1,1
this.nStartPos = nStart; }el7@Gv
this.nEndPos = nEnd; Xj9\:M-
nThreadID = id; a[_IG-l|i4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 X5pb9zRq
} uG$*DeZti
4mHk,Dd9,
$\+x7"pI
public void run() +70x0z2
{ h+R26lI1x
while(nStartPos < nEndPos && !bStop) b4qMTRnv
{ YP Qix
a]/KJn/B(
1}_4C0h\'
try{ YK\pV'&+
URL url = new URL(sURL); j1rR3)oP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q|{z9V<
httpConnection.setRequestProperty("User-Agent","NetFox"); ,!40\"A
String sProperty = "bytes="+nStartPos+"-"; Z;<:=#
httpConnection.setRequestProperty("RANGE",sProperty); KKq%'y)u^
Utility.log(sProperty); $cWt^B'
%*NED zy
-7KoR}Ck!
InputStream input = httpConnection.getInputStream(); .?vHoNvo
//logResponseHead(httpConnection); 8y']kVg
9}wI@
43 vF(<r&f
byte[] b = new byte[1024]; ..kFn!5(g
int nRead; +MZI\>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) WG&! VK
{ 9W0*|!tQ,+
nStartPos += fileAccessI.write(b,0,nRead); dS8ydG2
//if(nThreadID == 1) g< xE}[gF
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BRy3D\}
} +%f6{&q$
b"aF-,M>
hFo29oN
Utility.log("Thread " + nThreadID + " is over!"); A`#?Bj
bDownOver = true; eBH:_Ls_-^
//nPos = fileAccessI.write (b,0,nRead); dF[|9%)
} hF{gN3v5
catch(Exception e){e.printStackTrace ();} Fge["p?GF
} :>iN#)S
} {+m8^-T
,CI-IR2
q_6fr$-Qh
//打印回应的头信息 A%2B3@1'q
public void logResponseHead(HttpURLConnection con) HC}vO0X4
{ X}xf_3N "
for(int i=1;;i++) U9\\8
{ ohbU~R3{U
String header=con.getHeaderFieldKey(i); @ta:9wZ
if(header!=null) :%z#s
//responseHeaders.put(header,httpConnection.getHeaderField(header)); zYP6m3n
Utility.log(header+" : "+con.getHeaderField(header)); }SC&6B?G
else YKz#,
break; 9%Tqk"x?
} Zs]n0iwM'@
} {sf ,(.W
b*Q3j}cZ
$/lM %yXe
public void splitterStop() D;s%cL`
{ `#'j3,\6
bStop = true; wAw1K2d
} .'&pw}F
c:e3hJ
PZQAlO,
} Z;V(YK(WO.
{_-T!yb
">G*hS
/* t=X=",)f
**FileAccess.java HE35QH@/`
*//文件访问(定位，写) nw\C+1F
package NetFox; }AA">FF'y4
import java.io.*; %*szB$[3
L}CU"
8R%<~fq r
public class FileAccessI implements Serializable{ HAL\j5i
mI5J]hk
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;:_AOb31N
RandomAccessFile oSavedFile; J;NIa[a
long nPos; KJV8y"^=Q
tT!'qL.*
bZ1*:k2
public FileAccessI() throws IOException 7)]boW~Q
{ AmHj\NX$
this("",0); (~eS$8>.
} 6lCpf1>6@
jC_'6sc`
24nNRTI
public FileAccessI(String sName,long nPos) throws IOException :{N*Z}]
{ U#cGd\b
oSavedFile = new RandomAccessFile(sName,"rw"); 'iF%mnJ
this.nPos = nPos; f]#\&"
oSavedFile.seek(nPos); u178vby;l
} Ovc9x\N
JH{/0x#+
"5L?RkFi\
public synchronized int write(byte[] b,int nStart,int nLen) >t.Lc.
{ {?`7D:]`^
int n = -1; =y-yHRC7
try{ .SjJG67OyA
oSavedFile.write(b,nStart,nLen); F \ls]luN
n = nLen; ]:#=[CH
} T 5Zh2Q@
catch(IOException e) +Eh.PWEe
{ bS;_xDXd
e.printStackTrace (); McN[
} r}&&e BY f
FJDC^@Ne
J{^md0l
return n; Mib.,J~
} eM_;rMCr}
[:.wCG5
|,p"<a!+{w
} WM`3QJb
COsmVQ.
{Y@shf;
/* ~9 .=t'
**SiteInfoBean.java 7tXy3-~biz
*/ 'bJGQ[c
package NetFox; -'g>i
w") G:K
_$96y]Bpi
public class SiteInfoBean { ed`"xm
\894Jqh
#?Kw y
private String sSiteURL; //Site's URL 0: a2ER|J
private String sFilePath; //Saved File's Path $*942. =Q
private String sFileName; //Saved File's Name pdRM%ug
private int nSplitter; //Count of Splited Downloading File ?/OF=C#
~*7$aj
E+i*u
public SiteInfoBean() z'm}p
{//nSplitter的缺省值为5 UP^8Yhdo
//default value of nSplitter is 5 !{r2`d09n)
this("","","",5); @Suz-j(H
} T/g\v?>
!nSa4U,$w<
V.&F%(L
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /Ne#{*z)hO
{ GZ~Tl0U
sSiteURL= sURL; `=H*4I-"
sFilePath = sPath; sko7,&
sFileName = sName; ,)Q-o2(C
this.nSplitter = nSpiltter; P !i_?M
p/-du^:2
fr/EkL1Dl
} ):'wxIVGI
86OrJdD8
U;#KFZ+~
public String getSSiteURL() VKl,m ;&N
{ 6 X~><r
return sSiteURL; 8In\Jo$|q>
} |-x-CSN
n"htx|v
OW@%H;b
public void setSSiteURL(String value) Jz`jN~
{ BDI@h%tJb:
sSiteURL = value; :oZ<[#p"*
} 6p4BsWPx
2.aCo, Kb;
QcL@3QC
public String getSFilePath() U0_)J1Yp
{ D_d>A+
return sFilePath; xRD+!3
} ;[::&qf
G`zNCx.
Mpojabsh
public void setSFilePath(String value) p qz~9y~
{ Uw("+[5O0
sFilePath = value; zbxW U]<S?
} _=~u\$
p[C"K0>:_F
G1 "QX
public String getSFileName() k`m7j[A]l
{ +r3)\L{U
return sFileName; oIE 1j?
} :EV.nD7
eLSzGbKf
Ma|4nLC}
public void setSFileName(String value) t,7%| {
{ ekhv.;N~
sFileName = value; 3:x(2 A
} A0Mjk
X(ph$,[
X}k;(rb
public int getNSplitter() VO:4wC"7
{ R'v~:wNTNs
return nSplitter; ~A=zjkm
} pJ] Ix *M
0(7 IsG=t
>}V?GK36
public void setNSplitter(int nCount) tVRN3fJH
{ `3F#k[IR
nSplitter = nCount; BX?DI-o^h
} _iJ~O1qx,w
} 8z1z<\
h9Far8}
"r&,#$6W6
/* P$obID
**Utility.java `DY yK?R
*/ ,s~l; Gkj
package NetFox; 5?-HQoT)G
"ioO_
wmr?ANk
public class Utility { ^Gk`n
zTg\\z;
XZIapT
public Utility() '|IcL1c=I
{ +yP!7]
uxf,95<g)
$.jGO!
} X+;[Gc}(W
?Zb+xNKJ(
//线程睡眠 3NpB1lgh&:
public static void sleep(int nSecond) q}P@}TE
{ %l7[eZ{Y
try{ 63W;N7@
Thread.sleep(nSecond); j*DPW)RkKX
} LlX)xJ
catch(Exception e) zgAU5cw
{ IIR+qJ__|
e.printStackTrace (); [e+Y7M7
} KYpS4&Xh
} AY/.vyS
w jkh*Y
//日志 <<>+z5D+
public static void log(String sMsg) aRMlE*yW
{ ~n]5iGz
System.err.println(sMsg); h]oUY.Pf
} E'LI0fr
9z#8K zXg
qi,) l*?f
public static void log(int sMsg) '3l TI
{ B#V""[Y9
System.err.println(sMsg); *cb|9elF^
} E`fG9:6l]
} )7 p" -
=?OU^u`C
OXQ*Xpc
/* ?Y~t{5NJR
**TestMethod.java DhM=q
*/ $@z77td3
package NetFox; U?0|2hR~
H+[?{+"#@l
1 (<n^\J(
public class TestMethod { cI2Ps3~"Q
D^[l~K
z0}j7ns]
public TestMethod() <Q|\mUS6
{ ///xx/weblogic60b2_win.exe wp?:@XM
try{ kd'b_D[$H
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); xk,Uf,,>
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); x4q}xwH
SiteFileFetch fileFetch = new SiteFileFetch(bean); v}$Q
fileFetch.start(); layxtECP(
} q}@L"a`
catch(Exception e){e.printStackTrace ();} hZ45i?%
N1'`^ay$
egq,)6>
} w0BphK[
eft=k}
pQa51nc
public static void main(String[] args) O\=Z;}<N
{ F1yn@a "=J
new TestMethod(); );0
} p'h'Cz
} 8T3,56>
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