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)); )+~E8yK
} 9Vh_[^bR
for(int i=0;i<nEndPos.length-1;i++) a1x7~)z>zi
{ Z[IM<S9lz
nEndPos = nStartPos[i+1]; e6P[c=m #
} Rl@$xP
nEndPos[nEndPos.length-1] = nFileLength; -zC]^Ho@
} +l\<?
} T1~)^qQ
eK_*q-
>A jCl
//启动子线程 !EFBI+?&
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; y lL8+7W
for(int i=0;i<nStartPos.length;i++) <f%/px%1
{ 9Q[>.):
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kojG-M
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), W);W.:F
nStartPos,nEndPos,i); xh'^c^1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #( uj$[o
fileSplitterFetch.start(); <'*4j\*
} qZ\L
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z\Ui8jo:;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ml`vx
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %8D?$v"#Z
nEndPos = " + nFileLength); 1X@b?6
// fileSplitterFetch[nPos.length-1].start(); sc xLB;
?y_awoBd1
6"%qv`.Fp
//等待子线程结束 BlaJl[Piv
//int count = 0; B7 c[4
//是否结束while循环 .Ty,_3+{#p
boolean breakWhile = false; J:};n@<
,ep9V,+|
;X7i/DQ
while(!bStop) =R9*;6?N
{ 8-A|C< "
write_nPos(); SfDQ;1?
Utility.sleep(500); VK4/82@5
breakWhile = true; 8ui=2k(
TG]}X\c+V|
nEVbfNo0
for(int i=0;i<nStartPos.length;i++) (Jpm KO
{ lPS*-p#IZ
if(!fileSplitterFetch.bDownOver) &7][@v
{ )F E8D
breakWhile = false; 0M\NS$u(Y
break; 3H'*?|Y(#
} >EBC 2WJ
} K -E`y
if(breakWhile) gb_X?j%p7
break; ADBpX>
41'EA\V
,9vJtP+T+!
//count++; kH2oK:lN
//if(count>4) m<FK;
// siteStop(); [d:@1yc
} o*;2mFP
nP u`;no
+2yF|/WW#
System.err.println("文件下载结束！"); "WP% REE!
} QK7e|M
catch(Exception e){e.printStackTrace ();} =h[yAf
} 7vNtv9
?Ccw4]YO,=
g< )72-h
//获得文件长度 T/Q==Q{W:
public long getFileSize() "G kI5!
{ NDW8~lkL
int nFileLength = -1; "aA_(Ydzj
try{ Xq%*#)M;
URL url = new URL(siteInfoBean.getSSiteURL()); O\JD,w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {9;eH'e
httpConnection.setRequestProperty("User-Agent","NetFox"); >]?Jrs
oT!/J
:p$EiR
int responseCode=httpConnection.getResponseCode(); D"`[6EN[
if(responseCode>=400) NxB+?
{ *o2#eI
processErrorCode(responseCode); -fQX4'3R
return -2; //-2 represent access is error 4@/z
} gPp(e j7
/.)2d8,
)-)pYRlO
String sHeader; u#!GMZJN
H9:%6sds
8>dq=0:
for(int i=1;;i++) `$f2eB&
{ ##2`5i-x
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "B?R| Xg
//Utility.log(in.readLine()); ~zj"OG"zOw
sHeader=httpConnection.getHeaderFieldKey(i); S|) J{~QH
if(sHeader!=null) @Q3, bj
{ 1W0.Ufl)
if(sHeader.equals("Content-Length")) sSy$(%
{ \Nyr=<c
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); AtT"RG-6
break; W/a,.M
} 7y>(H<^>
} pMDH
else {70Ou}*
break; G V=OKf#
} Md?acWE*L
} c+wuC,
catch(IOException e){e.printStackTrace ();} uYabJqV
catch(Exception e){e.printStackTrace ();} ]'6'<S
K7S754m
ysl8LK
Utility.log(nFileLength); i.F8
]qMH=>pOsj
[JZ h*A
return nFileLength; Eh {up
} *F|i&2
F/xCG nP-
l_ZO^E~D_
//保存下载信息（文件指针位置） YV4 :8At1
private void write_nPos() MN\i-vAL8
{ EZ*t$3.T
try{ Dl&PL
output = new DataOutputStream(new FileOutputStream(tmpFile)); xg{VP7
output.writeInt(nStartPos.length); tr5'dX4]
for(int i=0;i<nStartPos.length;i++) K:uQ#W.&
{ f%L:<4
// output.writeLong(nPos); C)U #T)
output.writeLong(fileSplitterFetch.nStartPos); A3<^ U
output.writeLong(fileSplitterFetch.nEndPos); XnPJC'
} e"lD`*U8R
output.close(); yr%yy+(.k
} JR!Q,7S2!N
catch(IOException e){e.printStackTrace ();} A0UV+ -PP
catch(Exception e){e.printStackTrace ();} 5d%_Wb'
} 8F\~Wz7K
m'3OGvd
ZRX^^yN
//读取保存的下载信息（文件指针位置） f!mE1,eBEe
private void read_nPos() ruzMag)
{ /G{&[X<4U
try{ 8NxUx+]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 4bPqmEE
int nCount = input.readInt(); Kq8(d`g}
nStartPos = new long[nCount]; sC!1B6:
nEndPos = new long[nCount]; FoQ?U=er
for(int i=0;i<nStartPos.length;i++) 4v0dd p
{ F9v)R#u~
nStartPos = input.readLong(); "OVi /:*B
nEndPos = input.readLong(); 0 -!?W
} ^M[#^wv,
input.close(); =A$Lgk>|
} ?rAi=w&c
catch(IOException e){e.printStackTrace ();} !~?W \b\:
catch(Exception e){e.printStackTrace ();} v^<<[I2 C
} i0VhG:O;
[y_yPOv
r^fxyN2V
private void processErrorCode(int nErrorCode) }!eF
{ Nz3zsP$
System.err.println("Error Code : " + nErrorCode); BN_!Y)Fl
} 5z9JhU
9)ACgz&(
JJ^iy*v
//停止文件下载 %j~9O~-
public void siteStop() t^`<*H
{ 5Xp$yX =
bStop = true; 9`OG
for(int i=0;i<nStartPos.length;i++) ,G916J*XA
fileSplitterFetch.splitterStop(); V;M3z9xd
l :f9Ih
7~nIaT
} ON:LPf>"-
} 8yY"x ['
//负责部分文件的抓取 71K\.[ =-
**FileSplitterFetch.java Na~g*)uT$
*/ +J\L4ri k
package NetFox; R tXF
.q AQPL
~,(0h:8
import java.io.*; e-nWD
import java.net.*; Rh wt<
d)`nxnbMeM
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public class FileSplitterFetch extends Thread { 9itdRa==
n,CD4Nv
_Ym&UY.u#
String sURL; //File URL *O"%tp6
long nStartPos; //File Snippet Start Position !X \Sp}
long nEndPos; //File Snippet End Position M>`?m L
int nThreadID; //Thread's ID DR.3 J`?K
boolean bDownOver = false; //Downing is over nEjo,
boolean bStop = false; //Stop identical Z\ "Kd
FileAccessI fileAccessI = null; //File Access interface 3MS3O.0]/
j<. <S {
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException f 3nnXE"
{ F?yh23&_4
this.sURL = sURL; e["Z!D_H
this.nStartPos = nStart; GE/IaLo
this.nEndPos = nEnd; jUV#HT
nThreadID = id; $bF`PGR_
fileAccessI = new FileAccessI(sName,nStartPos);//定位 YHwVj?6W
} BDv|~NHs
eZa3K3^
VZ9e~){xA
public void run() (E2lv#[
{ }w|=c>'_}
while(nStartPos < nEndPos && !bStop) AxG?zBTFx
{ G#_(7X&
:epitpJ
e8WPV
try{ jgZX~D
URL url = new URL(sURL); I1eb31<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hr/xpQW
httpConnection.setRequestProperty("User-Agent","NetFox"); mI_ 6f~
String sProperty = "bytes="+nStartPos+"-"; ;ph+ZV
httpConnection.setRequestProperty("RANGE",sProperty); +iZ@.LI
Utility.log(sProperty); `Z;B^Y0
,d/CU
8EW`*+%=
InputStream input = httpConnection.getInputStream(); ];YglHH
//logResponseHead(httpConnection); ]ly)z[is"]
$=;bccIob
bi4^ zaCEE
byte[] b = new byte[1024]; ijR-?nrR
int nRead; ss|6_H =
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) VC_3ll]vr
{ XY$cx~
nStartPos += fileAccessI.write(b,0,nRead); Gc3PN
//if(nThreadID == 1) P~b%;*m}8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); vl#V-UW$4P
} 9fr&Yb=_o@
<E(-QJ
o$qFa9|Ec?
Utility.log("Thread " + nThreadID + " is over!"); Yp?a=R
bDownOver = true; qqO10~Xc
//nPos = fileAccessI.write (b,0,nRead); 8&`T<ECq>
} v]d?6g
catch(Exception e){e.printStackTrace ();} I%VV4,I&pK
} b{yH4)O
} V.E.~<7D\
Q xj|lr
6i?kkULBS
//打印回应的头信息 52q!zx E
public void logResponseHead(HttpURLConnection con) q(${jz4w
{ K7d1(.
for(int i=1;;i++) HeAc(_=C
{ "~i#9L/H
String header=con.getHeaderFieldKey(i); :#"OCXr
if(header!=null) U8.0L
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $D2Ain1
Utility.log(header+" : "+con.getHeaderField(header)); *(XgUJq+
else c+\Gd}IJq
break; QKL]O*
} QtO[g
} =-a?oH-
E!(`275s
'KN!m| z
public void splitterStop() Xf'
{ M#22Zfxq
bStop = true; @?($j)9}
} )Lv6vnT>
}~0{1&
[;kj,j
} iR4,$Nn>
R.n`R|NOd
5Dh&ez`oR'
/* $(<*pU
**FileAccess.java -^SD6l$
*//文件访问(定位，写) )I0g&e^Tzy
package NetFox; fjeE.
import java.io.*; E rRMiT
a}Iz
@tU>~y{E
public class FileAccessI implements Serializable{ [$Xu
GQc%OQc\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #7E&16Fk
RandomAccessFile oSavedFile; H6+st`{
long nPos; BRQ5
LnACce ?b
BM}a?nnoc
public FileAccessI() throws IOException t3h \.(mq
{ !un"XI0`t<
this("",0); rt4|GVa
} epm8N /
l.t.,:
5Qe}v
public FileAccessI(String sName,long nPos) throws IOException Y_ u7 0@`
{ ?\ i,JJO
oSavedFile = new RandomAccessFile(sName,"rw"); 39^uLob
this.nPos = nPos; (l,YI"TzT
oSavedFile.seek(nPos); ^gVbVz[17
} ZpP6Q
9R<J$e
{gq:sj>
public synchronized int write(byte[] b,int nStart,int nLen) /)HEx&SQmZ
{ ^SES')x
int n = -1; vN[m5)aT
try{ @x\gk5
oSavedFile.write(b,nStart,nLen); (4/`@;[
n = nLen; P24
} [+5SEr}
catch(IOException e) k@X As
{ [O =)FiY-
e.printStackTrace (); Ql!6I(
} eXtF[0f
~s^6Q#Z9|
fTnyCaB
return n; 1</t #r
} Zi'8~iEH
P<w>1 =
q.Aw!]:!
} Nl>b'G96
7B>cmi
pLFL6\{g
/* {s^n|b}
**SiteInfoBean.java So0,)
*/ oI"Fpo
package NetFox; SX<>6vH&
N,'qMoNf
GVPEene
public class SiteInfoBean { 7*W$GCd8
SX94,5 _Q
AI`1N%Owi
private String sSiteURL; //Site's URL N=}Z#
private String sFilePath; //Saved File's Path RyIaT
private String sFileName; //Saved File's Name ;Z0cD*Jb
private int nSplitter; //Count of Splited Downloading File j-\^ }K.&
+=F);;!
oA^ ]x>
public SiteInfoBean() JL+[1=uE1L
{//nSplitter的缺省值为5 )eVDp,.^
//default value of nSplitter is 5 "g&l~N1$
this("","","",5); S| ?--vai_
} uaMmiR
RAJ|#I1
Kwmo)|7uPU
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;bu;t#
{ '48|f`8$
sSiteURL= sURL; eh# (}v
sFilePath = sPath; -cC(d$y
sFileName = sName; Q? |MBTo
this.nSplitter = nSpiltter; k{&E}:A
=cX"gI[
X|0`$f
} vG=$UUh@~
*`/@[S2,cu
gG|1$
public String getSSiteURL() D+nj[8y
{ @G&xq"Fg7
return sSiteURL; 04LVa|Y@U
} :'Kx?Es
15yV4wHr
F973U
public void setSSiteURL(String value) <qZ+U4@I)
{ "U~@o4u;
sSiteURL = value; <cd%n-
} c35vjYQx0
o%s}jBo}
>Qu^{o
public String getSFilePath() R-0Ohj
{ J;9QDrl`
return sFilePath; QRix_2+
} I ywx1ac
GOgT(.5
]t0S_UH$
public void setSFilePath(String value) J:!Gf^/)
{ JqIv&W
sFilePath = value; Ya{1/AaM
} L{ ^@O0S
ed2&9E>9b
x@l~*6!K
public String getSFileName() |Y8o+O_`
{ +m},c-,=$w
return sFileName; >dH*FZ:c
} Uv$u\D+@[
J#5o
e;Z`&
public void setSFileName(String value) +opN\`
{ 9`VF [* 9
sFileName = value; '%7]xp
} {Z;GNMO:
jCa;g{#@
,3[<C)'[
public int getNSplitter() 2fA9L _:0
{ XsMphZnK
return nSplitter; Lu5.$b
} U6 R4UK
*XR~fs?/*W
}J lW\#
public void setNSplitter(int nCount) I=-;*3g6
{ 73<yrBxp
nSplitter = nCount; sM_e_e
} n#,l&Bx
} cC]1D*Bn
SZ){1Hu
pZn%g]nRD
/* _ h-X-s Y
**Utility.java 1#uw^{n
*/ ~;s)0M
package NetFox; Ku'U^=bVm:
Wuz~$SU
8hA=$}y&x
public class Utility { Hvk?(\x
QyQ8M1m
<us{4%
public Utility() p+?WhxG)
{ xo+z[OIlF
1MSu]) W
&d;$k
} y?hW#l~#X
vRs5-T
//线程睡眠 m$g^On
public static void sleep(int nSecond) C_)>VPD
{ iB-s*b<`~
try{ K>eG5tt
Thread.sleep(nSecond); 1=.?KAXR
} b>EUa> h
catch(Exception e) /ep~/#Ia
{ ?8/h3xV;
e.printStackTrace (); _\[G7
} ';F][x5j
} 1>{(dd?L
2N]s}/l
//日志 8m0sEV>
public static void log(String sMsg) >S]')O$c
{ ;{20Heuz
System.err.println(sMsg); tTt~W5lo
} TQH#sx
+Eg# 8/q
}lVUa{ubf
public static void log(int sMsg) E(#2/E6
{ h='=uj8o5
System.err.println(sMsg); NR{:4zJT
} 4r&~=up]
} '~0&m]N
a/fYD2uNo
_{%H*PxTn=
/* \eCdGx?
**TestMethod.java AJu.
*/ A\Gw+l<h,
package NetFox; RwWQ$Eb_s
lla96\R
" cg>g/
public class TestMethod { f_8~b0`
jEIL(0_H
yW 3h_08
public TestMethod() 0b'R5I.M
{ ///xx/weblogic60b2_win.exe t,_[nu(~8%
try{ r.5F^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); VXS9E383
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1,,-R*x
SiteFileFetch fileFetch = new SiteFileFetch(bean); =UY@,*q:c
fileFetch.start(); `0F IJT
} yM@cml6Ox
catch(Exception e){e.printStackTrace ();} mr? ii
\mloR '
$)!Z"2T
} r^)<Jy0|r
=B1!em|
;Lu|fQ#u*
public static void main(String[] args) \BW(c)Q
{ QR4o j
new TestMethod(); f`e.c_n(
} >Mn.|:DF]&
} HFOp4
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