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)); |;\pAZ2
} i-9W8A
for(int i=0;i<nEndPos.length-1;i++) ZYt1V"2VJ
{ R@#xPv4o%
nEndPos = nStartPos[i+1]; bVzJOBe
} Q.fUpa v
nEndPos[nEndPos.length-1] = nFileLength; T-h[$fxR_
} N)PkE>%X
} H^dw=kS
]L2b|a3
b7'l3mQjk
//启动子线程 eJ6 #x$I,
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9Vl}f^Gn
for(int i=0;i<nStartPos.length;i++) L9oLdWa(C
{ #=)!\
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `q`ah_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), GQjwr(
nStartPos,nEndPos,i); <oi'yr
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); AxeQv'e
fileSplitterFetch.start(); eSHsE3}h
} M!i*DU+SE
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =oM#]M'G+(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ox_DEg7l
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", e1y#p3 @d
nEndPos = " + nFileLength); zeq")A
// fileSplitterFetch[nPos.length-1].start(); =k,?+h~
`$XB_o%@
hk$I-
//等待子线程结束 YQyI{
//int count = 0; _s<s14+od
//是否结束while循环 ^IyYck'y+
boolean breakWhile = false; lr[T+nQ
vz|(KN[
-ssmj8:Q\|
while(!bStop) RNQq"c\
{ vexF|'!}0#
write_nPos(); ?|pP&8r
Utility.sleep(500); ]*gf$D
breakWhile = true; @!j6y(@
on"ENT
]Yf^O @<<>
for(int i=0;i<nStartPos.length;i++) gK(G1
{ }p-/R'
if(!fileSplitterFetch.bDownOver) t: oQHhO?
{ rqnxRq
breakWhile = false; +0j{$MPZ
break; j8 `7)^
} pQ!lY
} &}0QnO_mj
if(breakWhile) A:D9qp
break; x%9Ca)r?}
@'5*jXd
*4LRdLMn
//count++; mXS"nd30bD
//if(count>4) XA(.O|VZ
// siteStop(); |z"$^|@d?
} "FhC"}N
HG< z,gE 2
<L11s%5-
System.err.println("文件下载结束！"); :475FPy]
} {0np
catch(Exception e){e.printStackTrace ();} $}0!dR2
} e@;'#t
BlZB8KI~
AWPgrv/
//获得文件长度 ){z#Y#]dP
public long getFileSize() if*~cPnN
{ 9;uH}j8sE
int nFileLength = -1; N$v_z>6Z
try{ ssS"X@VZ \
URL url = new URL(siteInfoBean.getSSiteURL()); Mk=*2=d
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'Z=_zG/RX
httpConnection.setRequestProperty("User-Agent","NetFox"); H=*0KX{
5''k|B>
`HnZ{PKf
int responseCode=httpConnection.getResponseCode(); 7cWeB5e?O
if(responseCode>=400) :?LNP3}
{ 6rWq hIaI
processErrorCode(responseCode); zDEgC
return -2; //-2 represent access is error xLLTp7b(
} PC+Soh*
ki}Li*)7
.w _BA)
String sHeader; _(~LXk^C
64'QTF{D
#@5VT*/7
for(int i=1;;i++) 9z{g3m70@
{ S.`hl/
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); b/JjA
//Utility.log(in.readLine()); o0F,!}
sHeader=httpConnection.getHeaderFieldKey(i); i%F2^R@!q/
if(sHeader!=null) ZR0 OqSp]
{ =./PY10'
if(sHeader.equals("Content-Length")) 2~7*jA+Ab
{ F|/6;&*?M
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); k h*WpX
break; {oF;ZM'r
} ]q4LNo
} s]`6uyW"
else AZ^>osr
break; !FyO5`v
} :?= 1aiS
} Z%LS{o~LK.
catch(IOException e){e.printStackTrace ();} u rQvJ
catch(Exception e){e.printStackTrace ();} E BoC,{R#
jk_yrbLc
WBJn1
Utility.log(nFileLength); uPN^o.,/.
^jdtp
ZAeJTCCk
return nFileLength; |; mET
} 3D5adI<aq"
L0H^S)g
#lSGH 5Fp?
//保存下载信息（文件指针位置） }?Pa(0=U
private void write_nPos() "}%j'
{ /NR*<,c%
try{ p[%~d$JUq
output = new DataOutputStream(new FileOutputStream(tmpFile)); a #s Nd
output.writeInt(nStartPos.length); V4CA*FEA
for(int i=0;i<nStartPos.length;i++) xiQc\k$
{ vl}}h%BC
// output.writeLong(nPos); yLnTIE3)
output.writeLong(fileSplitterFetch.nStartPos); tQyQ+1
output.writeLong(fileSplitterFetch.nEndPos); S:xs[b.ZZ
} J|o<;9dg1
output.close(); Sx Bo%
} }TuMMO4+
catch(IOException e){e.printStackTrace ();} f*hnzj
catch(Exception e){e.printStackTrace ();} ?}W#j
} A,4} $-7
Bd;EI)JT
[xGL0Z%)t
//读取保存的下载信息（文件指针位置） 'cIFbjJ
private void read_nPos() qT4`3nH:
{ N>P" $
try{ FOPmvlA\-<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Oq3t-omXS
int nCount = input.readInt(); 8(A k
nStartPos = new long[nCount]; }095U(@
nEndPos = new long[nCount]; |\"%Dy[m
for(int i=0;i<nStartPos.length;i++) :'fK`G 6
{ KM^}d$x}s
nStartPos = input.readLong(); @Y(7n/*
nEndPos = input.readLong(); l#w0-n%S
} $SniQ
input.close(); GIR12%-EO
} ]i `~J
catch(IOException e){e.printStackTrace ();} +_f813$C
catch(Exception e){e.printStackTrace ();} la]Zk
} s <$*A;t
}y*rO(cu7G
Q2@yUDd!
private void processErrorCode(int nErrorCode) M[R'
{ N$ 2Iz
System.err.println("Error Code : " + nErrorCode); Dl}va
} IY2f$YV
sP8_Y,
@Hp=xC9V
//停止文件下载 j2n 4; m
public void siteStop() J+hifO
{ X%B2xQM5
bStop = true; ^c sOXP=Yp
for(int i=0;i<nStartPos.length;i++) 8{CBWXo$)
fileSplitterFetch.splitterStop(); _9iF`Q
q }9n.
&23t/`
} 2&F H8
} e#tWQM3
//负责部分文件的抓取 z}7U>y6`
**FileSplitterFetch.java 3+D4$Y"
*/ H.2aoZ-w
package NetFox; 6b4]dvl_
@Z9>E+udQ
?T[K{t;~jo
import java.io.*; ` B+Pl6l)F
import java.net.*; |c,'0V,"cH
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]=]`Mnuxb
public class FileSplitterFetch extends Thread { n(Ry~Xu_
Ymg,NkiP0
Ng1[y4R}
String sURL; //File URL Mj |"+(
long nStartPos; //File Snippet Start Position -/6Ms%O
long nEndPos; //File Snippet End Position {=E,.%8
int nThreadID; //Thread's ID 7!8R)m^1[
boolean bDownOver = false; //Downing is over H^w Inkf>
boolean bStop = false; //Stop identical G\S_e7$/
FileAccessI fileAccessI = null; //File Access interface %0eVm
brt`oR
ZL- ` 3x
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException YoRD9M~iG~
{ +0n,>eDjg^
this.sURL = sURL; A)o%\j
this.nStartPos = nStart; xo(3<1mD
this.nEndPos = nEnd; Ns`:=
nThreadID = id; ]4-t*Em
fileAccessI = new FileAccessI(sName,nStartPos);//定位 KHt#mQy)9
} TZ@S?r>^
m9f[nT
N< 7
public void run() A ]~%<=b
{ =:v5` :
while(nStartPos < nEndPos && !bStop) (W$>!1~
{ Ezw<
uF\f>E)/N%
.&c!k1kH
try{ MG0d&[
URL url = new URL(sURL); >WW5;7$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); U~[ tp1Z)
httpConnection.setRequestProperty("User-Agent","NetFox"); u69s}yZ
String sProperty = "bytes="+nStartPos+"-"; -Mufo.Jz1o
httpConnection.setRequestProperty("RANGE",sProperty); \"hP*DJ"
Utility.log(sProperty); ,zH\&D$>u
.ID9Xd$fky
Ewczq1%l:
InputStream input = httpConnection.getInputStream(); a'A'%+2
//logResponseHead(httpConnection); E,:E u<
T6p2=o&p
91j.%#[v'
byte[] b = new byte[1024]; wDS(zG
int nRead; [^E{Yz=8,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |+(Hia,X
{ 8n)3'ok
nStartPos += fileAccessI.write(b,0,nRead); \KPwh]0
//if(nThreadID == 1) /2e,,)4g
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); LuW^Ga"E
} ?>o|H-R~5Z
.LHzaeJCX
7FD.3/
Utility.log("Thread " + nThreadID + " is over!"); nfzKUJY
bDownOver = true; Pi:=0,"XOp
//nPos = fileAccessI.write (b,0,nRead); {oc7Chv=/H
} /QCyA%y
catch(Exception e){e.printStackTrace ();} 04cNi~@m
} :#zv,U&OC
} >n^[-SWJCT
n^Sc*7
qQ "O;_
//打印回应的头信息 f.y~Sew
public void logResponseHead(HttpURLConnection con) 9 ]W4o"
{ =)Q0=!%-
for(int i=1;;i++) '=eE6=m^K
{ =3Hv
String header=con.getHeaderFieldKey(i); <E.$4/T
if(header!=null) :Y;\1J<b1
//responseHeaders.put(header,httpConnection.getHeaderField(header)); C2 ] x
Utility.log(header+" : "+con.getHeaderField(header)); %!e;sL~&
else :},/D*v
break; \4e6\6 +
} znl_~:.4]X
} k_<8SG+`
h8lI#Gs
^9C9[$Q
public void splitterStop() jL[ hB
{ AE"E($S`
bStop = true; d(-$ { c
} gwepaW
-'OO6mU
WaRYrTDv64
} [d_sd
on q~wEr
Xqac$%[3
/* HBFuA.",
**FileAccess.java q;V1fogqI)
*//文件访问(定位，写) U0M>A
package NetFox; !7K-Kqn
import java.io.*; @Sl!p)
\#A=twp
CXsi
public class FileAccessI implements Serializable{ !r8Jo{(pb
9$xEktfV
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2F[;Z*&
RandomAccessFile oSavedFile; Z)U#5|sf
long nPos; (qP !x 2j
):_x
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public FileAccessI() throws IOException Mlpq2I_x
{ y{eZrX|
this("",0); 6L6Lk
} 8elT/Wl
KcB?[
a`w)awb
public FileAccessI(String sName,long nPos) throws IOException [^gSWU
{ Xm`K@hJ@
oSavedFile = new RandomAccessFile(sName,"rw"); XKsG2>l-W
this.nPos = nPos; o4kNDXP#S
oSavedFile.seek(nPos); g(:y_EpmLH
} ~P5!VNJ;r
nDvny0^a
ubhem(p#
public synchronized int write(byte[] b,int nStart,int nLen) fxLhVJ"b
{ ^3`98y.Q
int n = -1; @ %z5]w
try{ ?.A6HrAPB
oSavedFile.write(b,nStart,nLen); uF T\a=
n = nLen; ftq~AF
} }}qR~.[
catch(IOException e) 9wKz p
{ r/Pg,si
e.printStackTrace (); q9Y0Lk
} 0;TMwE
xiRTp:>
j.CC.[$g
return n; ?=IbiT
} CWkm\=
#G#gB
oRu S_X
} j7-#">YL
t9pPG{1
@V:b Co
/* 4 qW)R{%
**SiteInfoBean.java dm$:xE":
*/ 72-@!Z0e
package NetFox; V43JY_:
. ~|^du<X
dy`~%lX?
public class SiteInfoBean { w#b~R^U
"Ln\ZYB]
;U`HvIch
private String sSiteURL; //Site's URL b'-gy0
private String sFilePath; //Saved File's Path hV8A<VT
private String sFileName; //Saved File's Name cRg$~rYd
private int nSplitter; //Count of Splited Downloading File 8'cDK[L
mI`dZ3h
%)aDh }
public SiteInfoBean() Bv=Z*"Fv
{//nSplitter的缺省值为5 2=3iA09px
//default value of nSplitter is 5 Ta[}k/zW
this("","","",5); b'Uaj`Sn
} )O&$-4gL'
0^[$0]Mt[
(8ymQ!aY
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) RZ.5:v6
{ 5g&'n
sSiteURL= sURL; er<~dqZ}]
sFilePath = sPath; QnGJ4F
sFileName = sName; XnG!T$
this.nSplitter = nSpiltter; ?NwFpSB2
(^Ln|3iz
!9N%=6\
} >ab=LDoM
PHOW,8)dZh
BW*zj=N%
public String getSSiteURL() @)0gXg
{ +<|w|c
return sSiteURL; ~gAx
} v]1rH$
7)]G"m{
6$Dbeb
public void setSSiteURL(String value) ~.Gk:M
{ ~>EVI=?
sSiteURL = value; "h#=ctCx"
} 9!OpW:bR|
&,)tD62s
r9U1O@c
public String getSFilePath() cP Y^Bf5)
{ AuCVpDH
return sFilePath; =wQ=`
} 0'<S7?~|
qnlj~]NV
'F~u \m=E
public void setSFilePath(String value) {J]|mxo
{ &d2/F i+
sFilePath = value; WZr~Pb9
} 'SY&-<t(
83n: h08
(/Mc$V
public String getSFileName() %|I|Mc
{ 8?$2;uGL
return sFileName; K$Ph$P@
} o?3R HP47
O<hHo]jLF
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public void setSFileName(String value) ^#4s/mdVO
{ Dz{e@+>M
sFileName = value; ymzm x$o=
} j.6kjQN
s*IfXv
gU?)
public int getNSplitter() V~=)#3]`[
{ :QVGY^c
return nSplitter; qkIU>b,B
} qEAF!iB]L
]VvJ1Xn0
gY9"!IVe+
public void setNSplitter(int nCount) pR"qPSv'
{ #RF=a7&F
nSplitter = nCount; (yP55PC O$
} fo.m&mKgo
} wGvgMZ]?'
e0L;V@R
D}T,z
/* T?Y\~.+99
**Utility.java Pio^5jhB6
*/ L,6Y=?
package NetFox; |6>_L6t
o$O,#^
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public class Utility { `y}d)"!
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lIz_0rE
public Utility() z(3"\ ^T
{ qN@a<row&~
j;)6uia*A
^mi4q[PM
} Y9;Mey*oW
E: GJ$I
//线程睡眠 4*x!B![]y
public static void sleep(int nSecond) lQBM0|n
{ ^>Y%L(>
try{ ^%&x{F.
Thread.sleep(nSecond); @@wx~|%
} 1c#'5~nB
catch(Exception e) >|)0Amt
{ v=tj.Vg
e.printStackTrace (); Yys~p2
} bSf(DSqx
} bZ.N7X PH
@@IA35'tc
//日志 "Vq]|j,B/c
public static void log(String sMsg) U$)Hhn|X
{ K//T}-Uub
System.err.println(sMsg); /y)"j#-eW
} G%!\ p:w
6;cY!
S |>$0P4W(
public static void log(int sMsg) J4"swPf
{ {~fCqP.2
System.err.println(sMsg); WEtA4zCO
} 1~DD9z
} Reu{
V wVQ|UH
RX5.bVp eE
/* [fi'=Cb
**TestMethod.java QaWHz
*/ -I-Uh{)j
package NetFox; ,6;xr'[o*
Xexe{h4t_>
JhCkkw
public class TestMethod { GrR0RwnH)?
hNnX-^J<o
xDJ+BQ<1A
public TestMethod() NOr <,
{ ///xx/weblogic60b2_win.exe dAr)%RZ
try{ ZQ~myqx,+L
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); rEyz|k:
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); c5E#QV0&v~
SiteFileFetch fileFetch = new SiteFileFetch(bean); D2</^]3Su
fileFetch.start(); LkGf|yd_
} B>Cs&}Y!
catch(Exception e){e.printStackTrace ();} `{U%[$<[W
Ae j
4r[pMJiq
} $54=gRo^
]eYd8s+
"[*S?QO(L
public static void main(String[] args) mA(nyF
{ QSHJmk 6L
new TestMethod(); &_9YLXtMi;
} ;GE26Ymqly
} %1\v7Xw{9
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