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)); @/$mZ]|T
} F|P2\SPL
for(int i=0;i<nEndPos.length-1;i++) 1v2wP2]|;
{ n+Ag|.,|
nEndPos = nStartPos[i+1]; <*(~x esPS
} p+8]H %
nEndPos[nEndPos.length-1] = nFileLength; 7vj[ AOq3l
} z%Z}vWn
} &g& &-=7)
=l7LEkR
( ?/0$DB
//启动子线程 GV[%P
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7abq3OK+`
for(int i=0;i<nStartPos.length;i++) Z:/S@ry
{ Qgx~'9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TJ;v}HSo
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =dA T^e##
nStartPos,nEndPos,i); (ZEVbAY?i
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |%RFXkHS
fileSplitterFetch.start(); GU[Cq=k
} `=KrV#/758
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zi-+@9T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); TS[Z<m
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ok6e=c '
nEndPos = " + nFileLength); :T{or-
// fileSplitterFetch[nPos.length-1].start(); 8dA/dMQ
GrQl3 Xi
8V|-BP5^
//等待子线程结束 zfo.S[R@
//int count = 0; @nT8[v
//是否结束while循环 w5*18L=O\
boolean breakWhile = false; teB{GR
_b5iR<f
bZG$ biq
while(!bStop) u-K5
{ hPk+vvXtK
write_nPos(); F`-[h)e.
Utility.sleep(500); kcOpO<oE
breakWhile = true; @B^'W'&C
]yIy~V
<.v6w*+{/
for(int i=0;i<nStartPos.length;i++) n9J>yud|
{ [KE4wz+s{
if(!fileSplitterFetch.bDownOver) BuvBSLC~
{ B0KM~cCPQP
breakWhile = false; g8x8u|
break; \)#3S $L~
} &qpA<F@7
} * ;M?R?+
if(breakWhile) )xK!i.
break; b,`\"'1
nWl0R=
mPD'"
//count++; uf>w*[m5
//if(count>4) @'rO=(-b
// siteStop(); Ucy9fM
} ;C{_T:LS
*AA1e}R{B
y]+A7|
System.err.println("文件下载结束！"); GbE3:;JI
} vOj$-A--qU
catch(Exception e){e.printStackTrace ();} d{trO;%#f
} dog,vUu
7,4x7!
Rd$<R
//获得文件长度 <'B^z0I,
public long getFileSize() Bf}_ Jw-=
{ vJ'ho
int nFileLength = -1; s6]f#s5o
try{ bc"N
URL url = new URL(siteInfoBean.getSSiteURL()); POG5x
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ' FK"-)s
httpConnection.setRequestProperty("User-Agent","NetFox"); Wm,,OioK
fE:2MW!)*
[5 V
int responseCode=httpConnection.getResponseCode(); -s1VlS/
if(responseCode>=400) d{m0uX56
{ Fi`:G}
processErrorCode(responseCode); W!(Q_B
return -2; //-2 represent access is error Xm-63U`w5
} zKutx6=aj
51,m^veO
,]Ma,2
String sHeader; dkLR Q
1_QO>T'
:h3JDQe:.
for(int i=1;;i++) xVe!
{ CP'-CQ\Q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); B::?
//Utility.log(in.readLine()); "osYw\unI
sHeader=httpConnection.getHeaderFieldKey(i); dWUu3
if(sHeader!=null) 'YeJGzsJp
{ OG+$F
if(sHeader.equals("Content-Length")) b2Hpuej
{ d]^i1
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); AK!G#ug
break; S=2,jPX2r
} EGt)tI&
} ex1ecPpN
else LQjqwsuN{
break; WDZi @9X_
} vKC>t95
} 4kM<L}J#
catch(IOException e){e.printStackTrace ();} 'yNp J'
catch(Exception e){e.printStackTrace ();} GND[f}
g;h&Xkp
<gy'@w?
Utility.log(nFileLength); 0d2%CsMS"D
tFQFpbI
$3ILVT
return nFileLength; KOQTvJ_#
} Bz{ g4!ku
/b|sv$BN
5-*]PAC
//保存下载信息（文件指针位置） 9wC; m:
private void write_nPos() k y98/6
{ c>SeOnf
try{ X@)lPr$a
output = new DataOutputStream(new FileOutputStream(tmpFile)); q|l|gY1g)
output.writeInt(nStartPos.length); {V8Pn2mlo
for(int i=0;i<nStartPos.length;i++) {JgN^R<5<f
{ OOCeZ3yF(
// output.writeLong(nPos); kWd'gftQ
output.writeLong(fileSplitterFetch.nStartPos); t/Fe"T[,V
output.writeLong(fileSplitterFetch.nEndPos); UU;:x"4
} z#4g,)ZX
output.close(); E'G>'cW;x
} =-qsz^^a-
catch(IOException e){e.printStackTrace ();} v`&Z.9!Tz^
catch(Exception e){e.printStackTrace ();} ob{pQx7
} ~#CCRUhM
J (h>
1GdD
//读取保存的下载信息（文件指针位置） l_c?q"X
private void read_nPos() lu_Gr=#O
{ 5o/rV.I
try{ : [y(<TLw
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); m"R(_E5
int nCount = input.readInt(); g8Z14'Ke
nStartPos = new long[nCount]; Eg*3**gTO
nEndPos = new long[nCount]; ^U}0D^jDeE
for(int i=0;i<nStartPos.length;i++) o[#a}5Y
{ >gl.(b25C
nStartPos = input.readLong(); (zBQ^97]
nEndPos = input.readLong(); Z3dd9m#.]
} B/OO$=>(
input.close(); V1.F`3h~
} x8Sq+BY
catch(IOException e){e.printStackTrace ();} G$ FBx
catch(Exception e){e.printStackTrace ();} ~<aB-.d
} C)j)j&
.KN]a"]
8GldVn.u
private void processErrorCode(int nErrorCode) >Il`AR;D
{ ,X^_w g
System.err.println("Error Code : " + nErrorCode); Zi)b<tM q
} 919g5f`
QGd- 9UEA]
p0K;m%
//停止文件下载 ]aNnY?qW5
public void siteStop() <Z'hZ
{ lG9ARRy(=
bStop = true; 3;NRW+
for(int i=0;i<nStartPos.length;i++) 7VcVI? ?
fileSplitterFetch.splitterStop(); n^N]iw{G
M-N2>i#
lWvd"Vlt
} gQWX<
} 2r,'4%G
//负责部分文件的抓取 Wi^rnr'Ss
**FileSplitterFetch.java I?>T"nV +'
*/ )\vHIXnfJ1
package NetFox; *a!!(cZZ
dn_OfK
8n5nHne
import java.io.*; P-[K*/bPw
import java.net.*; "\;wMR{
M%xL K7
s2~dmZ_B|_
public class FileSplitterFetch extends Thread { *GP_ut%
S:/RYT"
1i:g /H
String sURL; //File URL OL5HofgNm
long nStartPos; //File Snippet Start Position on?/tHys
long nEndPos; //File Snippet End Position +E|ouFI
int nThreadID; //Thread's ID 9^ p{/Io
boolean bDownOver = false; //Downing is over |+-i'N9
boolean bStop = false; //Stop identical % Au$E&sj
FileAccessI fileAccessI = null; //File Access interface aa8Qslm
bK\WdG\;
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?4e6w
{ #Hi]&)p_
this.sURL = sURL; @BUqQ9q:
this.nStartPos = nStart; AijTT%
this.nEndPos = nEnd; $?AA"Nz
nThreadID = id; aLt{X)?
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }Xj_Y]T
} d~-p;i
*)1Vs'!-
'%C.([
public void run() Y>Hl0$:=
{ uhB!k-ir
while(nStartPos < nEndPos && !bStop) orH0M!OtS!
{ ApYud?0b
x ;,xd
FLI8r:
try{ %@n8 ?l4
URL url = new URL(sURL); _G #"B{7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;+34g6
httpConnection.setRequestProperty("User-Agent","NetFox"); ^z}lGu
String sProperty = "bytes="+nStartPos+"-"; bDBO+qA
httpConnection.setRequestProperty("RANGE",sProperty); zL`uiZl
Utility.log(sProperty); `(/saq*
(0#F]""\e
=4<S8Cp
InputStream input = httpConnection.getInputStream(); X|E+K
//logResponseHead(httpConnection); ;c Co+(
aroVyUs3j
9<h]OXv
byte[] b = new byte[1024]; ds;cfj[
int nRead; .#55u+d,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 4z%#ZIy3
{ rn:zKTyhw
nStartPos += fileAccessI.write(b,0,nRead); !L. K)9I
//if(nThreadID == 1) jS3(>
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F] ?@X
} 4UD=Y?zK
U?mf^'RE
ct4 [b|
Utility.log("Thread " + nThreadID + " is over!"); i4zV(
bDownOver = true; Qy5Os?9"
//nPos = fileAccessI.write (b,0,nRead); [~c'|E8Q
} Ocwp]Mut&
catch(Exception e){e.printStackTrace ();} rp @
} ( *>/w$%
} bk"k&.C^+
{&=qM!2e
M&/aJRBS
//打印回应的头信息 wK'!xH^
public void logResponseHead(HttpURLConnection con) OssR[$69
{ TT2cOw
for(int i=1;;i++) k l!?/M
{ \!JS7!+
String header=con.getHeaderFieldKey(i); EEs-&
if(header!=null) WAB0e~e:|Q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }PQSCl^I
Utility.log(header+" : "+con.getHeaderField(header)); 0GX10*t.
else 4s~HfxYT
break; =v4r M0m,
} >$naTSJq
} 4[#6<Ixf
\}Acq;
/$9 :L
public void splitterStop() ^+%tlX_+.
{ 9#&W!f*qO|
bStop = true; l^ 0_>R
} hzQ+9-qA
/}$T38
:Wg-@d
} (#bp`Kih
8VuZ,!WH#
l{6` k<J(
/* =,4 '"
**FileAccess.java K6v $#{$6
*//文件访问(定位，写) aM{@1mBm
package NetFox; 8pk#sJ51
import java.io.*; f(6UL31
8wX+ZL:9
i}`_H^
public class FileAccessI implements Serializable{ d]CviQUq
J-tq8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 p:JRQT"A
RandomAccessFile oSavedFile; hD6JW-
long nPos; L$lo~7<]
tS (i711
6h2x~@
public FileAccessI() throws IOException t{Hh&HX
{ !@pV)RUv7
this("",0); =! N _^cb
} <AMb!?Obh
E7gHi$
-@SOo"P
public FileAccessI(String sName,long nPos) throws IOException <TR/ `
{ }PI35i1!t
oSavedFile = new RandomAccessFile(sName,"rw"); LG=X)w)W4S
this.nPos = nPos; =R&)hlm
oSavedFile.seek(nPos); }dX/Y/
} (_w %
4ZI!,lv*
3}B5hht"D
public synchronized int write(byte[] b,int nStart,int nLen) ADYx.8M|9i
{ N7*CP|?E
int n = -1; D3S+LV
try{ -9OMn}w/*
oSavedFile.write(b,nStart,nLen); (Qk&g"I
n = nLen; [,O`MU
} !Ea&]G
catch(IOException e) cBifZv*l
{ ^]$$)(jw
e.printStackTrace (); j:3EpD@GS
} d"H<e}D
_W0OM[
aKv[
return n; 50LHF%
} A&<?
)=jT_?9b
908ayfVI
} T8$%9&j!UE
v"u7~Dw#1
5v|H<wPp
/* })20Zld}a
**SiteInfoBean.java &/](HLdF
*/ iV?` i
package NetFox; J`w]}GlH
T3PX gL)o
^|wT_k\
public class SiteInfoBean { WP0 #i~3*
la'e[t7
Z#-k.|}
private String sSiteURL; //Site's URL `n 3FT=
private String sFilePath; //Saved File's Path \F 3C=M@:
private String sFileName; //Saved File's Name M#OHY*
private int nSplitter; //Count of Splited Downloading File /Q?~Q0{)es
dgS4w@)@V;
M^z=1YrMd
public SiteInfoBean() i?F[||O"$
{//nSplitter的缺省值为5 =~J"kC
//default value of nSplitter is 5 Ovvny$
this("","","",5); `Kh]x9Z
} tM&n3MWQ
\n#]%X5c
Hqvc7-c6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) >b>MKm>q
{ PzjaCp'
sSiteURL= sURL; q@w{c=
sFilePath = sPath; 1g1?zk8zO
sFileName = sName; 4P|$LkI
this.nSplitter = nSpiltter; 6|,e%
<tFSF%vG=
um;:fT+
} >SvDgeg_7f
uie~'K\y
[UMLx
public String getSSiteURL() ?VB#GJ0M9
{ eGLO!DdxZ
return sSiteURL; U,PZMz`2j
} k, f)2<
<EtUnj:qK8
]nUR;8
public void setSSiteURL(String value) cTM$ZNin
{ vYDSu.C@a
sSiteURL = value; &vCeLh:s
} ]/Vh{d|I&
)s7bJjT0=X
V1<ow'^i
public String getSFilePath() %`#G92Z_
{ C\ vC?(n
return sFilePath; QU.0Elw
} OB~C}'^$
P/ci/y_1
D?^540,b
public void setSFilePath(String value) wa!zv^;N*
{ P+h6!=nD7
sFilePath = value; ^|#>zCt^
} S?L#N
Q!yb16J
+'|{1gB
public String getSFileName() %tV32l=
{ /}Yqf`CZy
return sFileName; Hle\ON
} :r&iMb:Ra
wUoiXi09
,9mgYp2
public void setSFileName(String value) e8,{|a
{ }!8nO;
sFileName = value; d<x1*a
} ;hwzYXWF
!tU'J"Zy
!6HuFf
public int getNSplitter() :[xvlW29
{ L}$z/jo
return nSplitter; zG#wu
} `FZF2.N
mQ}Gh_'ps
kn}zgSO
public void setNSplitter(int nCount) {)xWD%
{ GW3>&j_!d
nSplitter = nCount; xYI;V7
} .n`( X#,*l
} 6\4Z\82
l&L,7BX
RNTa XR+Zn
/* rVH6QQF=\
**Utility.java ~-_i
*/ gWOt]D&#/
package NetFox; SWs3SYJ\
T~Ly^|Ihz
fG&=Ogy
public class Utility { jY/ARBC}H
URA0ey`
]tB@kBi "
public Utility() f#$|t>
{ ZjD)?4
H_w%'v&
v^SsoX>WMH
} ?^9BMQ+
R4{-Qv#8 q
//线程睡眠 E1 |<Pt
public static void sleep(int nSecond) "_< 9PM1t
{ 8[zb{PRu
try{ >;4!O%F
Thread.sleep(nSecond); M-J<n>hl
} sb^mLH] 3
catch(Exception e) l!?yu]Yon
{ !`&\Lx_
e.printStackTrace (); A1),el-^5
} T#EFXHPr
} #y1Bx,
#DFp[\)1
//日志 =gjDCx$|
public static void log(String sMsg) 53Yxz3v
{ I[0!SIqY
System.err.println(sMsg); M:|8]y@
} /=)L_
e[1>(l}Ss
a460|w6
public static void log(int sMsg) c8ZA5|
{ Qz,|mo+
System.err.println(sMsg); w^q7n
} (ChD]PWQ
} E.`6oX\L|
!_~UvxM+
5\hd4
/* m#e*c[*G
**TestMethod.java V`#.7uUP
*/ C\}/"
package NetFox; lpgd#vr
y('k`>C
8(f:U@BS
public class TestMethod { 6>`c1 \8f
+G*JrwJ&=
c_.-b=zm
public TestMethod() 9QwKakci
{ ///xx/weblogic60b2_win.exe mwC=o5O
try{ bsS:"/?>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]<XR]FHx)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); g/~XCC^F?
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~"K,7sw!Y
fileFetch.start(); O o8qyW
} +=BAslk
catch(Exception e){e.printStackTrace ();} S6xgiem
7 oQ[FdRn*
mi,&0xDea
} e6E?t[hEeS
;_O)p,p
(JUZCP/\
public static void main(String[] args) `P}9i@C
{ R=]d%L8
new TestMethod(); xQ4%e[/
} u92^(|
} xSMt*]=9
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