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)); 5P('SFq'=
} NP.qh1{NP
for(int i=0;i<nEndPos.length-1;i++) 6!U~dt#a
{ E_z,%aD[
nEndPos = nStartPos[i+1]; L'a s^Od
} je:J`4k$
nEndPos[nEndPos.length-1] = nFileLength; |jWA >S
} &`"uKO]
} DfOigLG*
d| {<SRAI
MqWM!v-M
//启动子线程 #Guwbg
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #LYx;[D6
for(int i=0;i<nStartPos.length;i++) i&}LuF8
{ grd fR`3
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #b&=CsW`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), aXbj pb+
nStartPos,nEndPos,i); hg^klQD
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c)QOgXv
fileSplitterFetch.start(); .?F`H[^)^u
} 7pH[_]1"
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x;7p75Wm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <Lle1=qQ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @a]`C $6
nEndPos = " + nFileLength); "+&@iL
// fileSplitterFetch[nPos.length-1].start(); M7gqoJM'Q
m}m|(;T
@<S'f<>g
//等待子线程结束 %CrpUx
//int count = 0; 61b<6r0o
//是否结束while循环 ?I.bC
boolean breakWhile = false; 57N<OQWf
@<1T&X{Z!
?`SBGN;
while(!bStop) 5)4?i p
{ 5e'**tbKH
write_nPos(); taSYR$VJ
Utility.sleep(500); :y!{=[>M(
breakWhile = true; yAJrdY"
UXS+GAWU
f*[Uq0?
for(int i=0;i<nStartPos.length;i++) cPl$N5/5
{ cc3+Wx_
if(!fileSplitterFetch.bDownOver) _ =(v? 2:?
{ f./j%R@
breakWhile = false; oFu( J
break; ub{Yg5{3S\
} aXD|XE%
} fqm6Pd{:(
if(breakWhile) !;U}ax;AF
break; I"jub kI=Z
y(r(q
~HX'8\5
//count++; Ed"p|5~
//if(count>4) ;uU 8$
// siteStop(); .!1E7\
} CakB`q(8
s.!gsCQme
VC NQ}h[D
System.err.println("文件下载结束！"); 3_Re>i
} lHgmljn5u
catch(Exception e){e.printStackTrace ();} L3C'q
} `[4{]jX+<
Z@#kivcpz
rdm&YM`J
//获得文件长度 ,HW[l.v
public long getFileSize() eOd'i{f@F
{ X4v0>c
int nFileLength = -1; OWHHN<
try{ UZW)%
URL url = new URL(siteInfoBean.getSSiteURL()); OmECvL'Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n\4sNoFI
httpConnection.setRequestProperty("User-Agent","NetFox"); xNxSgvco,
H[iR8<rhQ
KQrG|<J
int responseCode=httpConnection.getResponseCode(); +r]2.
if(responseCode>=400) vj<JjGP
{ ?7aeY5p
processErrorCode(responseCode); b U>.Bp]
return -2; //-2 represent access is error , *Z!Bd8
} Al}%r85
Ykj+D7rA:
qmGLc~M0
String sHeader; ncij)7c)u
p w`YMk
* @'N/W/8
for(int i=1;;i++) wEb10t,
{ >VvA&p71b
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7brC@+ZD
//Utility.log(in.readLine()); RZ:=';
sHeader=httpConnection.getHeaderFieldKey(i); P?YcZAJT*
if(sHeader!=null) IaR D"oCH
{ :.fm LL
if(sHeader.equals("Content-Length")) xAAwH@ +
{ "?{=|%mf
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .|3&lb6
break; vHx[:vuq:
} A]s|"Pav,
} H<wkD9v}H5
else q{+Pf/M5
break; -f8iq[F5
} Z[zRZ2'i5
} $2pkh%
catch(IOException e){e.printStackTrace ();} =E-V-?N\
catch(Exception e){e.printStackTrace ();} ]9NA3U7F
6n$g73u<=3
Z {*<Gx
Utility.log(nFileLength); ?hnxc0~P
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h2m@Q={
return nFileLength; xIa8Ac
} IpI|G!Y,
qv$m5CJvK
]F*fQNcjy
//保存下载信息（文件指针位置） I=9sTR)
private void write_nPos() 9g`o+U{
{ jB%aHUF;
try{ -1tiy.^$F
output = new DataOutputStream(new FileOutputStream(tmpFile)); xr1,D5
output.writeInt(nStartPos.length); TKZ[H$Z
for(int i=0;i<nStartPos.length;i++) 8iUj9r_
{ _T.k/a
// output.writeLong(nPos); 'P3jUc)
output.writeLong(fileSplitterFetch.nStartPos); z[0B"f
output.writeLong(fileSplitterFetch.nEndPos); }w/6"MJ[n
} phqmr5s^H
output.close(); QlK]2r9
} ~-o[v-\
catch(IOException e){e.printStackTrace ();} &`Ek-b!7
catch(Exception e){e.printStackTrace ();} =^`?O* /;
} ^ah9:}Ll
) i=.x+Q
f#b;s<G
//读取保存的下载信息（文件指针位置） ])NQzgS
private void read_nPos() *'hJ5{U
{ 6~c:FsZ)
try{ :[.**,0R
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *32hIiCm
int nCount = input.readInt(); =/MA`>
nStartPos = new long[nCount]; jdAjCy;s!
nEndPos = new long[nCount]; M)j.Uu
for(int i=0;i<nStartPos.length;i++) &'<e9
{ 8XdgtYm
nStartPos = input.readLong(); S!+}\*
nEndPos = input.readLong(); eNX!EN(^
} 8t >nL
input.close(); bE>"DPq
} nb}rfd.
catch(IOException e){e.printStackTrace ();} -|_MC^)
catch(Exception e){e.printStackTrace ();} {>n\B~*,"C
} b]k9c1x
M.?[Xpa
~l"]J'jF"H
private void processErrorCode(int nErrorCode) bn6WvC3?
{ <3C/t|s
System.err.println("Error Code : " + nErrorCode); I::|d,bR!
} ]YWz;Z
JBt2R=
H[D<G9:
//停止文件下载 F;sZc,Y,^
public void siteStop() I> BGp4AQ
{ .6[7D
bStop = true; }YCpd)@
for(int i=0;i<nStartPos.length;i++) 0<#>LWaM_
fileSplitterFetch.splitterStop(); =C 7WQ
LeaJ).Maw
qvG@kuz8g5
} 4Be'w`Q {
} rc`}QoB)R
//负责部分文件的抓取 _UGR+0'Q\
**FileSplitterFetch.java jiqE^j3;
*/ H?_>wQj&
package NetFox; sFV&e->AN\
6&`hf >
h1 pEC
import java.io.*; 5L\&"['
import java.net.*; dpSNh1
=bJ7!&
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public class FileSplitterFetch extends Thread { TP{2q51yM
B"?ivxM:U
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String sURL; //File URL \45F;f_r6
long nStartPos; //File Snippet Start Position bYAtUEv
long nEndPos; //File Snippet End Position zv0bE?W9
int nThreadID; //Thread's ID 1s/548wu
boolean bDownOver = false; //Downing is over 6W[~@~D=
boolean bStop = false; //Stop identical %8{nuq+c
FileAccessI fileAccessI = null; //File Access interface wl7 (|\-
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3t9Weo)
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .C,D;T{
{ `Vl9/IEk
this.sURL = sURL; YJu~iQ`i
this.nStartPos = nStart; ACOn}yH
this.nEndPos = nEnd; gE: ?C2
nThreadID = id; v6P2v
fileAccessI = new FileAccessI(sName,nStartPos);//定位 f9D01R fo
} =~_
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public void run() sm"s2Ci=}
{ ,0a\Ka{^
while(nStartPos < nEndPos && !bStop) *}) W>
{ 7!Qu+R
|p.|zH
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try{ qWM+!f
URL url = new URL(sURL); S#:l17e3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N@0cn q:"
httpConnection.setRequestProperty("User-Agent","NetFox"); ny1;]_X_
String sProperty = "bytes="+nStartPos+"-"; KX J7\}
httpConnection.setRequestProperty("RANGE",sProperty); DS=$* Trk
Utility.log(sProperty); zf;sdQ;4
'^)}"sZ@G
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InputStream input = httpConnection.getInputStream(); 8W Etm}
//logResponseHead(httpConnection); 10_#Z~aU
7-gT:
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byte[] b = new byte[1024]; =;Dj[<mJ45
int nRead; ly:2XvV3~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) T~L&c
{ f@[qS7ok
nStartPos += fileAccessI.write(b,0,nRead); N "}N>xe2
//if(nThreadID == 1) J6Vx7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _"*}8{|
} 6H=gura&
;5DDV6
aW-6$=W
Utility.log("Thread " + nThreadID + " is over!"); :V1j*)
bDownOver = true; tI)|y?q
//nPos = fileAccessI.write (b,0,nRead); .cm2L,1h
} "VDMO^
catch(Exception e){e.printStackTrace ();} m?kyAW'|
} [ ou$*
} y @S_CB47
kH8/8
k.z(.uc=
//打印回应的头信息 <RKT |
public void logResponseHead(HttpURLConnection con) NSM7n= *nh
{ @VPmr}p:{
for(int i=1;;i++) l dqU#{
{ pH3<QNq5
String header=con.getHeaderFieldKey(i); }R11G9N.
if(header!=null) Z&O6<=bg!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); qVfl6q5
Utility.log(header+" : "+con.getHeaderField(header)); K)U[xS;<
else T<-_#}.Hn
break; Ss%1{s~ok
} R0%M9;>1
} AmC?qoEWQ7
Evd|_W-
cPv(VjS1;
public void splitterStop() axpZ`BUc
{ )+R n[MMp
bStop = true; wZs 2aa
} qV6WT&)T
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} UWidT+'Sa
J ZkQ/vp(
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/* a>x6n3{
**FileAccess.java *MB>,HU
*//文件访问(定位，写) g(Q1d-L4e
package NetFox; K|YB)y
import java.io.*; aCI3Tx&2qT
S*$?~4{R
{`Gd
public class FileAccessI implements Serializable{ `CI_zc=jx
2;u i'B
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 xJ2I@*DN
RandomAccessFile oSavedFile; a|"Uw `pX+
long nPos; i[@13kr
2j}DI"|h
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public FileAccessI() throws IOException [q_+s
{ _&/ {A|n
this("",0); a6-.|tt#t
} pQKSPr
=MMd&
}zx ~
public FileAccessI(String sName,long nPos) throws IOException VX&PkGi?o
{ _bi)d201
oSavedFile = new RandomAccessFile(sName,"rw"); 0~z\WSo
this.nPos = nPos; Xh>($ U
oSavedFile.seek(nPos); U3N9O.VC
} }Uwji
marZA'u%B1
Z Cjw)To(
public synchronized int write(byte[] b,int nStart,int nLen) U2A 82;Z
{ )9:5?,SO
int n = -1; EG;E !0
try{ RQb}t,
oSavedFile.write(b,nStart,nLen); {eV8h}KIl
n = nLen; `/ayg:WSU
} uINdeq7|F
catch(IOException e) 0'fswa)
{ XS">`9o!
e.printStackTrace (); ".tL+A[
} Ff%V1BH[
@(~:JP?KNC
UhpJGO
return n; s0^(yEcq
} ,_fz)@)
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u}gavG l
} AoeRoqg&#
3_~iq>l
\7uM5 k}l
/* yB2h/~+
**SiteInfoBean.java p.SipQ.P
*/ z.!N|"4yr
package NetFox; L_NiU;cr%
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public class SiteInfoBean { L"NHr~
XS[L-NHG
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private String sSiteURL; //Site's URL 8s@N NjV
private String sFilePath; //Saved File's Path %)x9u$4W2
private String sFileName; //Saved File's Name sfj+-se(K.
private int nSplitter; //Count of Splited Downloading File wDZ<UP=X
12KC4,C&1i
o^\Pt<~W
public SiteInfoBean() 0(D^NtB7
{//nSplitter的缺省值为5 M .b8 -`V
//default value of nSplitter is 5 4 "HX1qP
this("","","",5); ba);f[>
} 2t-w0~O
n%s%i-[5B
\A"o[A2v
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /.Ak'Vmi
{ %,kP_[!>Q
sSiteURL= sURL; ^ RA'E@"
sFilePath = sPath; rNii,_
sFileName = sName; }OL"38P
this.nSplitter = nSpiltter; `t&{^ a&Y"
@#)` -]g
"y,YC M`
} kg[%Q]]
8w&-O~M
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public String getSSiteURL() 2gPqB*H
{ DH-M|~.sf^
return sSiteURL; d9#Vq=H /
} xzm]v9k&
z%%O-1
!hBpon
public void setSSiteURL(String value) jO-?t9^
{ bf"'xn9
sSiteURL = value; ?m |}}a
} GQqGrUQ*}
2T~cOH;T
CWn\KR
public String getSFilePath() D(#f`Fj;
{ G@[8P?M=Z
return sFilePath; mll:rWC)
} B7C3r9wj
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public void setSFilePath(String value) !Rn6x $_
{ Ey&H?OFiP
sFilePath = value; elOeXYO0
} G%<}TI1}
wA=r]BT
,#A(I#wL~
public String getSFileName() $J`O-"M
{ <v:VA!]
return sFileName; 5ilGWkb`'X
} tnRf!A;m
oJz2-PmX
5i!Q55Yv=,
public void setSFileName(String value) 3!"N;Q"
{ )/H;5 cn
sFileName = value; >='/%Ad
} I&;>(@K
U(#<D7}
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public int getNSplitter() ~s!Q0G^G
{ )'_[R@ThB
return nSplitter; b(H{i}{]
} rs&]46i/p
*@2Bh4
VY0.]t
public void setNSplitter(int nCount) K p3}A$uV
{ tIsWPt]Y
nSplitter = nCount; t]yxLl\
} OXEk{#Uf[3
} m&UP@hUV-
zM9#1^X
H U|.5tP
/* -@W9+Zf5
**Utility.java ,fkvvM{mq
*/ PsY![CPrW
package NetFox; -8TJ:#|N
Xwm3# o.&)
_pvB$&
public class Utility { lvs XL
[GLH8R
BG>Y[u\N
public Utility() oL<#9)+2*
{ )ZG;.j
AM}R#86
4xy\
} bx0.(Nv/X
u6qK4*eAD
//线程睡眠 :t}\%%EbmE
public static void sleep(int nSecond) R'Sd'pSDN
{ h)KHc/S
try{ CdolZW-!"
Thread.sleep(nSecond); SepjF
} {%V(Dd[B6
catch(Exception e) {i5?R,a)
{ Yh":>~k?SY
e.printStackTrace (); sVLvnX,
} 9BCW2@Kp
} FaL\6w
1^~&"s U
//日志 j]Auun
public static void log(String sMsg) $^Fl*:6
{ Wv;0PhF
System.err.println(sMsg); sZ.<:mu[
} (m~>W"x/
= tv70d'
4"d,=P.{
public static void log(int sMsg) I= mz^c{
{ <Vat@e
System.err.println(sMsg); Wh[QR-7Ew
} `zd,^.i5~
} vCzZjGBY
)`u17 {
KII{GDR]
/* j{@O%fv=
**TestMethod.java 4ot<Uw5
*/ $%<{zWQm
package NetFox; ?|nl93m
vB:\ZX4
IpP%WW u
public class TestMethod { @=-(H<0
P"YdB|I
eV;r /4
public TestMethod() th?+TNb^
{ ///xx/weblogic60b2_win.exe 9^gYy&+>6]
try{ i2F7O"f.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0YH5B5b
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =7Ln&tZ
SiteFileFetch fileFetch = new SiteFileFetch(bean); }0'=}BE
fileFetch.start(); 3]Z1kB
} N5 ME_)
catch(Exception e){e.printStackTrace ();} Ltlp9 S
VUb>{&F[
q6zVu(
} 7CIN!vrC|1
/x VHd
@CprC]X
public static void main(String[] args) l45/$G7
{ LUOjaX
new TestMethod(); JGs:RD'
} j-<]OOD
} j3j?2#vR
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