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)); [b`6v`x
} ')nnWlK
for(int i=0;i<nEndPos.length-1;i++) %2yAvGa1
{ elbG\qXBp
nEndPos = nStartPos[i+1]; .C5@QKU
} T"W9YpZ
nEndPos[nEndPos.length-1] = nFileLength; %ejeyc
} iVeQ]k(u
} ="B n=>
.5g}rxO8
oCJbkt=
//启动子线程 !Z/$}xxj
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; H`D f
for(int i=0;i<nStartPos.length;i++) F!~l MpuE
{ )vHi|~(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V} bM!5 H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), R=35 7^[R
nStartPos,nEndPos,i); ){tPP$-i=
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |s`Kd-'|q
fileSplitterFetch.start(); ?L`ZKRD
} K^ 6+Ily
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v>at/ef
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .;slrg(5F
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Ed=}PrE
nEndPos = " + nFileLength); &s-VSu7
// fileSplitterFetch[nPos.length-1].start(); $,P\)</VR
=>YvA>izE
!`C%Fkq
//等待子线程结束 dzxI QlP
//int count = 0; "/y|VTV"
//是否结束while循环 AM?Ec1S #a
boolean breakWhile = false; 5bBCpNa
DR{]sG
ji##$xC
while(!bStop) A`C-sD>
{ _m7co :
write_nPos(); {]M>Y%j48
Utility.sleep(500); )G4rJ~#@
breakWhile = true; ;KS`,<^-
ZeTL$E[E}
FF@`+T
for(int i=0;i<nStartPos.length;i++) irmwc'n]
{ cUC17z2D
if(!fileSplitterFetch.bDownOver) ._ih$=
{ ^^ j/
breakWhile = false; _3U|2(E
break; l4Y1(
} >p |yf.G
} xSOoIsL[
if(breakWhile) MHNe>C-!q
break; gA:[3J,[;
CK Mv7
iUCwKpb9
//count++; U IQ 6SvM
//if(count>4) e/P4mc)
// siteStop(); CKN8z
} 2*YP"Ryh
\6LcVik
{9'hOi50
System.err.println("文件下载结束！"); [,nfAY
} J=VyyUB
catch(Exception e){e.printStackTrace ();} kdd7Xbw-
} kDg{>mf
wXcMt>3
(NM6micc
//获得文件长度 <>&89E%j'
public long getFileSize() dh?S[|='
{ XqX I(q^
int nFileLength = -1; s+N^PX3
try{ ,0.|P`|w
URL url = new URL(siteInfoBean.getSSiteURL()); &*ZC0V3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'XEK&Yi1
httpConnection.setRequestProperty("User-Agent","NetFox"); #!Ze\fOC
?KCxrzf
Z]p8IH%~92
int responseCode=httpConnection.getResponseCode(); 2| $k`I,
if(responseCode>=400) h^v9|~ZJ'7
{ hOl=W |)v
processErrorCode(responseCode); `:R-[>5P8
return -2; //-2 represent access is error F\Y,JUn[G
} |zb`&tv}
oX#9RW/ >I
-P*xyI
String sHeader; -D;lS 6
BM.-X7)
Q+HZ?V(
for(int i=1;;i++) @F~0p5I
{ pB[%:w/@l:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .oEFX8
//Utility.log(in.readLine()); EuLXtq
sHeader=httpConnection.getHeaderFieldKey(i); A mvw`u>
if(sHeader!=null) 0|GpZuGO9
{ a2[8wv1
if(sHeader.equals("Content-Length")) $xQ"PJ2
{ yX3PUO9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); phe"JNML
break; IF& PGo
} G1p43
} F"Uh/EO<
else U~Xf=f_Q$
break; !>q?dhw@
} )< l\jfx e
} df!+T0
catch(IOException e){e.printStackTrace ();} FSFFk~
catch(Exception e){e.printStackTrace ();} N JXa_&_
jjYM3LQcdP
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Utility.log(nFileLength); 5a8JVDLX^
'+tKvTU;
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return nFileLength; VVgsLQd
} Ko@zk<~"[
Jm%mm SYK
*ZX!EjICk
//保存下载信息（文件指针位置） OA!R5sOz"
private void write_nPos() vP-3j
{ VPdwSW[eM
try{ @pTD{OW?
output = new DataOutputStream(new FileOutputStream(tmpFile)); SHytyd
output.writeInt(nStartPos.length); Q +R3H,
for(int i=0;i<nStartPos.length;i++) U2VV[e)Z!
{ B<(Pd
// output.writeLong(nPos); OuMco+C
output.writeLong(fileSplitterFetch.nStartPos); >7"$}5d
output.writeLong(fileSplitterFetch.nEndPos); "^Y6ctw
} }7-7t{G
output.close(); `Fz\wPd
} &3jBE--
catch(IOException e){e.printStackTrace ();} Lf[G>0t&n
catch(Exception e){e.printStackTrace ();} !-F^VGD(8
} 7 kEx48
Oi6f8*,
P=&'wblm?
//读取保存的下载信息（文件指针位置） : x>I- 3G
private void read_nPos() P"oYC$
{ f<'n5}{RO0
try{ a$~IQ2$|6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); E(7@'d{o
int nCount = input.readInt(); B:B8"ODV
nStartPos = new long[nCount]; a|8|@,
nEndPos = new long[nCount]; ,LoMt ]H
for(int i=0;i<nStartPos.length;i++) &b5T&-C<
{ vYYS.ve
nStartPos = input.readLong(); dK[*
nEndPos = input.readLong(); _{[k[]
} MV% :ES?
input.close(); M' a&
} '2wXV;`
catch(IOException e){e.printStackTrace ();} ,}eRnl\
catch(Exception e){e.printStackTrace ();} sM#!Xl;
} V h Z=,m
;r gH}r
x-w`KFS
private void processErrorCode(int nErrorCode) j2< !z;2
{ eo>/
System.err.println("Error Code : " + nErrorCode); dCa}ITg
} [q|?f?Zl
:D<:N*9i
unCt4uX^
//停止文件下载 Vf"O/o}hq,
public void siteStop() x{=[w`
{ ERUs0na]
bStop = true; ;% /6Y~/
for(int i=0;i<nStartPos.length;i++) q"{Up
fileSplitterFetch.splitterStop(); !w @1!Xpn1
=Jsg{vI
<$RS*n
} _8,vk-,'
} I{`KKui<M
//负责部分文件的抓取 gJ<@;O8zu0
**FileSplitterFetch.java fBHkLRFH
*/ = 4BLc
package NetFox; 73&]En
$ /}:P
8#X?k/mzU
import java.io.*; Qw3a"k-
import java.net.*; ,[Dh2fPM,
4w;rl(s
cmwzKu%
public class FileSplitterFetch extends Thread { kHt!S9r
&:;/]cwj
u@GRN`yn
String sURL; //File URL nQ:ml
long nStartPos; //File Snippet Start Position *,O :>Z5I
long nEndPos; //File Snippet End Position +O;OSZ
int nThreadID; //Thread's ID TSc~$Q]
boolean bDownOver = false; //Downing is over }}kS~ w-#
boolean bStop = false; //Stop identical a)I=U[
FileAccessI fileAccessI = null; //File Access interface C ffTv
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException )![f\!'PI
{ n/KI"qa]9
this.sURL = sURL; K[iY{
this.nStartPos = nStart; &*jxI[
this.nEndPos = nEnd; dAu^{1+2
nThreadID = id; 1TK #eU
fileAccessI = new FileAccessI(sName,nStartPos);//定位 D)H?=G
} +Fu@I{"A
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public void run() 4@/q_*3o
{ H B::0l<
while(nStartPos < nEndPos && !bStop) sDzD 8as
{ *b$z6.
sf.E|]isW
xHM&csL
try{ M3ecIVm8(
URL url = new URL(sURL); ir?Uw:/f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bqZ?uvc3
httpConnection.setRequestProperty("User-Agent","NetFox"); O4 +SD
String sProperty = "bytes="+nStartPos+"-"; yDCooX0
httpConnection.setRequestProperty("RANGE",sProperty); H3 A]m~=3
Utility.log(sProperty); C$N4
[oQ`HX1g
V\iIvBpWg
InputStream input = httpConnection.getInputStream(); q;1VF;<"vH
//logResponseHead(httpConnection); Y(#d8o}}#
]>VJ--fH
RT.wTJS;
byte[] b = new byte[1024]; WU+Jo@]y
int nRead; "}]GQt< F
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _|^&eT-u
{ d&[M8(
nStartPos += fileAccessI.write(b,0,nRead); *pcbwd!/
//if(nThreadID == 1) ;55tf l
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?L<UOv7;t
} vWnHC
vOvxQS}dBp
P+*rWJ8gQ
Utility.log("Thread " + nThreadID + " is over!"); y]z)jqX<
bDownOver = true; ?1-n\ka
//nPos = fileAccessI.write (b,0,nRead); ="#:=i]
} Y\z^\k
catch(Exception e){e.printStackTrace ();} zVc7q7E
} \,@Yl.,+
} V'HlAQr
#VQGN2bK.
'-nuH;r
//打印回应的头信息 C$AIP\j- )
public void logResponseHead(HttpURLConnection con) 3]:p!Y`$
{ By51dk7
for(int i=1;;i++) S5*~r@8h
{ *0Wi^f
String header=con.getHeaderFieldKey(i); &9RW9u "
if(header!=null) e-Ybac%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 6g~o3
Utility.log(header+" : "+con.getHeaderField(header)); i-i}`oN
else MrKU,-
break; \Age9iz&
} :o.x=c B
} <6}f2^
c]g<XVI
>'2w\Uk~:
public void splitterStop() aowPji$H
{ W[1f]w3
bStop = true; PtPGi^
} Dj,+t+|
&G7)s%q
w{:Oa7_A
} C%95~\Ds
+}`O^#<qLX
<QkN}+B=
/* UuOLv;v
**FileAccess.java 6'No4[F 4n
*//文件访问(定位，写) T ,O<LFv
package NetFox; !q=Q~ea
import java.io.*; RIVL 0Ig
#T$'.M
_Pfx_+
public class FileAccessI implements Serializable{ S}v{^vR
>F\rBc&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 XTi0,e]5{u
RandomAccessFile oSavedFile; $3]E8t
long nPos; "zeJ4f
{-v\&w
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public FileAccessI() throws IOException Jc"$p\ $-
{ 11@2;vw
this("",0); LjH&f 4mY
} $D, wO
FkxhEat8
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public FileAccessI(String sName,long nPos) throws IOException Z_^Kl76D
{ x3I%)@-Z
oSavedFile = new RandomAccessFile(sName,"rw"); c~pUhx1(
this.nPos = nPos; o trTrh
oSavedFile.seek(nPos); tXG4A$(2&
} ~Q$c!=
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:AqnWy
public synchronized int write(byte[] b,int nStart,int nLen) 1<qVN'[
{ .X<"pd*@e
int n = -1; 1n"+~N^\
try{ RESGI}u
oSavedFile.write(b,nStart,nLen); "13 :VTs[5
n = nLen; s:jL/%+COZ
} ;FgEE%
catch(IOException e) `~aLSpB65
{ U+RCQTo
e.printStackTrace (); R/Dy05nloe
} C_^R_
7AtXG^lK
#Zavdkw=d
return n; /4-eoTxy
} c@o/Cv
/P8eI3R
i:Z.;z$1
} Bn#HJ17/#
]N(zom_0d
Dpp52UnTE
/* T`'3Cp$q
**SiteInfoBean.java d$?n6|4
*/ ,f/IG.
package NetFox; ?j4,^K3
++{+ #s6
Kt* za
public class SiteInfoBean { /=Uv
"$:y03V
/?dQUu^z
private String sSiteURL; //Site's URL RY/ Z~]
private String sFilePath; //Saved File's Path 73sAZa|
private String sFileName; //Saved File's Name @qhg[= @
private int nSplitter; //Count of Splited Downloading File y1"^S
0&rH 9
Mi/'4~0Y
public SiteInfoBean() GLKN<2|2@y
{//nSplitter的缺省值为5 5W]N]^v
//default value of nSplitter is 5 f$@".
this("","","",5); \$HB~u%dr
} ~tj7zI6
P2:Q+j:PX
X"khuyT_
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8JFkeU%yO
{ ah6F^Kpl{
sSiteURL= sURL; %k;FxUKi
sFilePath = sPath; +!V%Q
sFileName = sName; DIu72\
this.nSplitter = nSpiltter; gmAKW4(
z#E,96R
NW>:Lz ?"
} ~{7NTW
2|NyAtPb5
QsF<=b~
public String getSSiteURL() \FY De
{ XOU-8;d
return sSiteURL; eg~^wi
} q}A3"$-F
+q=jB-eIx
S~(VcC$K
public void setSSiteURL(String value) <$3nD b-
{ . ;@)5"
sSiteURL = value; U#1yl6e\I
} &lfF!
#/v_h6$
Y)5uK:)^
public String getSFilePath() uy-Ncy
{ xo 'w+Av
return sFilePath; eWk2YP!
} zt?wn*_
NizJq*V>
98}vbl31j
public void setSFilePath(String value) 6=lQT 9u{
{ fu "z%h]
sFilePath = value; vAhO!5]>\
} :pjK\
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public String getSFileName() rHdP4:n
{ 7<Js'\Z
return sFileName; |Gs-9+'y
} 2?nyPqT3AM
:@8.t,|
! tPK"k
public void setSFileName(String value) 1:s~ ]F@
{ ;Wh[q*A
sFileName = value; [^=8k2
} `IRT w"
!9cPNIi
+~{nU'
public int getNSplitter() 0m!ZJHe
{ dZYJ(7%
return nSplitter; nMoF;AdKm
} Oc+L^}elJ
4_:e+ ql
td$6:)
public void setNSplitter(int nCount) Cv7RCjMw
{ ~HI0<;r=eL
nSplitter = nCount; s ;Nu2aOp7
} XUNgt(OGR'
} & ~G
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F%$Ws>l
/* 00wH#_fm
**Utility.java uOUw8
*/ 2}\sj'0&
package NetFox; ^B=z_0 *
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public class Utility { g^^m a}i
C4TD@
pG=zGx4
public Utility() s"F,=]HQ!G
{ oqo8{hrdHk
)4~XZt1r
G%/cV?18
} Y k6WSurw
RXvcy<
//线程睡眠 H$iMP.AK
public static void sleep(int nSecond) \/%Q PE8
{ u}0t`w:
try{ xW )8mv?4n
Thread.sleep(nSecond); `fVA.%
} (P]^5D
catch(Exception e) V"p*Jd"w
{ ]= D
e.printStackTrace (); *4\ub:9
} #!j&L6
} sJYX[
jo:p*Q"F
//日志 bbA<Zp
public static void log(String sMsg) ~;a* Oxt
{ )p](*Z^
System.err.println(sMsg); GDe$p;#"9g
} >%A=b}VS
&G,v*5N8$K
r|$g((g
public static void log(int sMsg) "d*
{ dQo$^?
System.err.println(sMsg); `u)V9{
} 1fG@r%4
} uB!P>v6
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t)b>f~
/* :P'5_YSi
**TestMethod.java IiU|@f~k
*/ $S=OmdgR
package NetFox; cv&hT.1
z`6KX93
05DtU!3O
public class TestMethod { 7P(:!ce4-
1O{67Pf
RT9|E80
public TestMethod() 16{;24
{ ///xx/weblogic60b2_win.exe c9K\K~bk
try{ Jx,s.Z0@7,
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -O6o^Dk
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8;bOw
SiteFileFetch fileFetch = new SiteFileFetch(bean); uu#+|ZD
fileFetch.start(); o W [-?
} 4^A'A.0
catch(Exception e){e.printStackTrace ();} !b Km}1T
<Z wEdq
yw^,@'
} _z<q9:
Cr"hu;
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public static void main(String[] args) wjs7K|PK
{ q\G@Nn^
new TestMethod(); -rrg?4
} gNBI?xs`p
} EyiM`)!5
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