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)); vTEkh0Ys
} %Tb|Yfyr C
for(int i=0;i<nEndPos.length-1;i++) #G=QL(f>/
{ |*NrS<"
nEndPos = nStartPos[i+1]; [L(l++.z
} u_"h/)C'H
nEndPos[nEndPos.length-1] = nFileLength; -YyH"f
} r97[!y1gt
} Y fA\#N0;3
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//启动子线程 NXNon*"
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b . j^US^
for(int i=0;i<nStartPos.length;i++) HXHPz4
{ =eoxT
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N6[^62
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), .rm7Sd4K
nStartPos,nEndPos,i); Kx+Bc&X
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); LD~'^+W
fileSplitterFetch.start(); }gi'%e
} 5; [|k$ v
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r3_gPK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4Z<l>!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @<=#i
nEndPos = " + nFileLength); z=_{jjs
// fileSplitterFetch[nPos.length-1].start(); PI \,`^)y
o#) !b:/
L,pSdeq
//等待子线程结束 <xjv7`G7
//int count = 0; xm0#4GFUS
//是否结束while循环 J-<B*ot+lX
boolean breakWhile = false; B[B<U~I}
\=V[ba:q
cgeS)C7
while(!bStop) Le JlTWotC
{ f{c[_OR
write_nPos(); kte.E%.PE
Utility.sleep(500); :+Ax3
breakWhile = true; I=yj
AJd.K'=8
-*fYR#VQQB
for(int i=0;i<nStartPos.length;i++) l_-n&(N2<[
{ N>Y50
if(!fileSplitterFetch.bDownOver) Z;'.pU~
{ A<5`[<x$
breakWhile = false; WbWW=(N'd
break; MxEAs}MDv
} %=8(B.I!
} 2\\3<
if(breakWhile) @h$0S+?:
break; [(F<|f:n
^p zxwt
0P40K
//count++; ]"g >>N
//if(count>4) W.D3$
// siteStop(); `A _8nW)
} ,Z7Z!.TY!
s [F' h-y
=G F
System.err.println("文件下载结束！"); 7XWBI\SW
} $,,>R[;w
catch(Exception e){e.printStackTrace ();} }lTZq|;A
} WriN]/yD
Cj 2Xl
3@`H<tP'6o
//获得文件长度 <4e*3WSG
public long getFileSize() kok^4VV
{ H"rzRd;S
int nFileLength = -1; /+t[,
try{ &:I +]G/W
URL url = new URL(siteInfoBean.getSSiteURL()); LZC?383'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y2$;t'
httpConnection.setRequestProperty("User-Agent","NetFox"); Cm;qDvj+u
@IY?DO
&f<1=2dm
int responseCode=httpConnection.getResponseCode(); EN)A"
if(responseCode>=400) 7$'mC9
{ SKpPR;=q|:
processErrorCode(responseCode); J1p75c%
return -2; //-2 represent access is error 7(~H77
} kTZx-7~
U%t/wq
8{<[fZyC
String sHeader; [&qbc#L
a950M7
:6j :9lYL2
for(int i=1;;i++) *Z]WaDw
{ /4 LR0`A'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); W_,;eyo
//Utility.log(in.readLine()); ,ANK3n\
sHeader=httpConnection.getHeaderFieldKey(i); %L13Jsw
if(sHeader!=null) XCIa2Syo
{ +Sd,l>8\
if(sHeader.equals("Content-Length")) G(0y|Eq
{ i`KZ,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); IbJ[Og^Qyu
break; 5nx<,-N*BP
} Az< 9hk
} yD"0=\
else 2>}\XKF).
break; xOL)Pjo/m
} 8q?;Hg
} fQ36Hd?(5
catch(IOException e){e.printStackTrace ();} <@e+-$
catch(Exception e){e.printStackTrace ();} |[37:m
p + l_MB
3U~lI&
Utility.log(nFileLength); J/x@$'
+:,`sdv6o
rFq@]t3q
return nFileLength; N8XC~Dh{
} J,1osG<6x
},fo+vRM
u.kYp
//保存下载信息（文件指针位置） G?ugMl}
private void write_nPos() JOdwv4(3V
{ U$A7EFK'
try{ Q-`{PJ(p
output = new DataOutputStream(new FileOutputStream(tmpFile)); D!RE-w92X
output.writeInt(nStartPos.length); (}C^_q:7d
for(int i=0;i<nStartPos.length;i++) $,;S\JmWP
{ 7SK3
// output.writeLong(nPos); %[nR|a<
output.writeLong(fileSplitterFetch.nStartPos); zvGK6qCk
output.writeLong(fileSplitterFetch.nEndPos); TsX+. i'
} <4Q12:
output.close(); !b7'>b'J<1
} R#/?AD&
catch(IOException e){e.printStackTrace ();} e$Bf[F#;-
catch(Exception e){e.printStackTrace ();} :6W^ S/pf
} $Pd|6
9si}WqAw
^RV
//读取保存的下载信息（文件指针位置） _3.G\/>[K
private void read_nPos() p/hvQyE
{ |0L=8~M(j
try{ e?!L}^f6X
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); w#xeua|*I#
int nCount = input.readInt(); 7<3U?]0
nStartPos = new long[nCount]; z+k=|RMau
nEndPos = new long[nCount]; ,!I?)hwOC
for(int i=0;i<nStartPos.length;i++) rv}mD
{ 6QII&Fg
nStartPos = input.readLong(); U=kx`j>
nEndPos = input.readLong(); ~M ,{ _
} "]T$\PJun
input.close(); \TbsoWX
} +5HnZ?E\
catch(IOException e){e.printStackTrace ();} V#NG+U.B
catch(Exception e){e.printStackTrace ();} m ZtvG,
} KZF0rW
=naR{pI
NfTCpA
private void processErrorCode(int nErrorCode) hj&fQ}X
{ 5iQmZ[
System.err.println("Error Code : " + nErrorCode); zJ;>.0
} 6 u-$
/mn-+u`K
h(@R]GUX
//停止文件下载 <)O>MI' 4
public void siteStop() C,A!tj7@
{ &|.hkR2k
bStop = true; ]cm6 |`pz
for(int i=0;i<nStartPos.length;i++) Xnv@H:$mxk
fileSplitterFetch.splitterStop(); (#6AKr9K
&~~aAg
`KpFH.k.K
} c~}={4M]
} oZvA~]x9\
//负责部分文件的抓取 V@D]bV@4
**FileSplitterFetch.java Vd+td;9(
*/ u5w&X8x
package NetFox; jzs.+dAg
IKi{Xh]\
9u,8q:I.?
import java.io.*; G'f9N^w
import java.net.*; <4bz/^
j8GY`f#
E6Q]A~
public class FileSplitterFetch extends Thread { -<qxO
T[;;9z
1 -ZJT
String sURL; //File URL }zFf0.82
long nStartPos; //File Snippet Start Position Y[Q@WdE9
long nEndPos; //File Snippet End Position _1^8xFe2
int nThreadID; //Thread's ID mZ~qG5@/F
boolean bDownOver = false; //Downing is over }I]j&\
boolean bStop = false; //Stop identical kE/`n],1U
FileAccessI fileAccessI = null; //File Access interface 7J9l.cM3
Hm%g_Mt
DY9fF4[9a
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :{LAVMG&^
{ 9!9> ?Z
this.sURL = sURL; \dRzS@l
this.nStartPos = nStart; QyPg |#T2>
this.nEndPos = nEnd; X8/Tl\c
nThreadID = id; ]3*P:$Rq
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ha*X6R
} ~>V-*NT8
$<B +K
1O |V=K
public void run() |G(1[RNu
{ ?c!:81+\
while(nStartPos < nEndPos && !bStop) Dv&>*0B
{ xS'zZ%?
F4Zn5&.)
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try{ UVB/vqGg
URL url = new URL(sURL); 2-++i:, g
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); t|}O.u-&;~
httpConnection.setRequestProperty("User-Agent","NetFox"); aG%kmS&fv
String sProperty = "bytes="+nStartPos+"-"; 5m4DS:&
httpConnection.setRequestProperty("RANGE",sProperty); !(Krf
Utility.log(sProperty); (;aB!(_
[,=d7*b(l
_%Bz,C8
InputStream input = httpConnection.getInputStream(); No) m/17y
//logResponseHead(httpConnection); Sp:l;SGd
WsR+Np@c
?^ZXU0IkP
byte[] b = new byte[1024]; jM~Bu.7 i6
int nRead; TyF{tuF
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 2i\Q@h
{ 17}$=#SX
nStartPos += fileAccessI.write(b,0,nRead); V/PAi.GZ
//if(nThreadID == 1) Py|;kF~![
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j{"z4Y4
} +$47v$p
{`%hgR
5IW8=$k~.)
Utility.log("Thread " + nThreadID + " is over!"); *8bK')W
bDownOver = true; P;vxT}1
//nPos = fileAccessI.write (b,0,nRead); V<8K@/n@
} B0d%c&N${
catch(Exception e){e.printStackTrace ();} J~KX|QY.S
} 8eluO ?p
} %j7:tf=
k=[pm5ZvT~
0GZq`a7[
//打印回应的头信息 q"akrI38
public void logResponseHead(HttpURLConnection con) ['cz;2{:W
{ 4KXc~eF[M"
for(int i=1;;i++) XphE loL
{ !:WW
String header=con.getHeaderFieldKey(i); [4*1}}gW%5
if(header!=null) J8?2R^;{
//responseHeaders.put(header,httpConnection.getHeaderField(header)); n9%]-s\Hn
Utility.log(header+" : "+con.getHeaderField(header)); 5t\HJ`C1Z
else u%u&F^y
break; _;hf<|c
} OfTfNhpK
} 5RF4]$zT
w(U:U-MNe
ESTM$k}X
public void splitterStop() }7ehF6
{ zI^]esX!2_
bStop = true; qP3q
} [dB$U}SEj
*6Q|}b[qcD
+r]zs^'
} {tw+#}T a
\'Ssn(s
@PI%FV z~p
/* fRB5U'
**FileAccess.java +m)q%I>
*//文件访问(定位，写) &]F3#^!^
package NetFox; @MiH(.Dq
import java.io.*; }4&/VvN
Y-)xTn
${I*nh>=
public class FileAccessI implements Serializable{ +bA%
J0Z7l
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 3BdX
RandomAccessFile oSavedFile; 8w_7O>9
long nPos; ***a2Z/(
uo2'"@[e
! zL1;d
public FileAccessI() throws IOException tF7hFL5f
{ tGjhHp8}c
this("",0); NBYH;h P
} x|i_P|Z
k7@t{Cu0D&
>Lft9e
public FileAccessI(String sName,long nPos) throws IOException 8`=v.
{ s@8w-]"
oSavedFile = new RandomAccessFile(sName,"rw"); -TO\'^][X
this.nPos = nPos; w_hHfZ9E
oSavedFile.seek(nPos); 3Fs5RC~a
} &c>?~-!W
/3!fA=+
tyh@^7
public synchronized int write(byte[] b,int nStart,int nLen) %eg+F
{ H,QTYXi "
int n = -1; y7/F_{
try{ j$Ab>}g]
oSavedFile.write(b,nStart,nLen); E{E0Z9t7&
n = nLen; t)f-mQz)
} S<`I Jpkv
catch(IOException e) e}hmS1>H
{ 'n;OB4
e.printStackTrace (); )G~w[~
} V5i*O3a~
8|6 4R:
$q$7^r@
return n; i/H+xrCK
} C0jj(ku&
}}&#|)Yq
^uBxgWIC
} ? *>]")[>
*.#oxcll
>UDd @
/* ~PnTaAPJ
**SiteInfoBean.java .,0bE
*/ =WIJ>#Go<
package NetFox; 1vzb8.
#bX9Tu0
99xEm
public class SiteInfoBean { F@ Swe
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^r6!l.
private String sSiteURL; //Site's URL A@hppaP!
private String sFilePath; //Saved File's Path }e2VY
private String sFileName; //Saved File's Name vS\Nd1~?
private int nSplitter; //Count of Splited Downloading File SAYLG
ZJPmR/OV_
HpZ1xT
public SiteInfoBean() ziPR>iz-
{//nSplitter的缺省值为5 ",6M)3{|c
//default value of nSplitter is 5 #>lG7Ns|4
this("","","",5); #J (~_%Wi
} JN+_|`
jhu07HX_
kQ1w5mCh
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^9Qy/Er'
{ =X\^J
sSiteURL= sURL; &>d:R_Q]
sFilePath = sPath; >NYW{(j
sFileName = sName; wX >*H
this.nSplitter = nSpiltter; #$1Z
k:jSbbQ
I[)%,jd
} mKrh[nA
7xRl9
&xRo^iV?
public String getSSiteURL() Q></`QWpoB
{ L:XC
return sSiteURL; X+UJzR90
} "&/-N[is
c\a_VRN>r
'5&s=M_
public void setSSiteURL(String value) .<@8gNm3
{ #@<9S{F
sSiteURL = value; [8tL"G6s
} ^[:p|U2mA
1-lu\"H`
nRyU]=-X
public String getSFilePath() i&{DOI%w
{ k0Ol*L!p
return sFilePath; 2hzsKkrA {
} {~Rk2:gx
aDO!
y=?)n\f
public void setSFilePath(String value) (L^]Lk x)
{ S$QG.K:<!
sFilePath = value; i3rH'B-I.
} eek7=Z
|{CfWSB7~@
8Z(Mvq]f&
public String getSFileName() *98$dQR$
{ 6I@h9uIsze
return sFileName; n{6G"t:^l
} !pD*p)`s
0u\GO;
feQ **wI
public void setSFileName(String value) +v=C@2T
{ .l.a(_R
sFileName = value; j~!X;PV3
} ~l)-wNqR4r
J0@X<Lt U
Q~Hy%M%R3
public int getNSplitter() tQS5hwm*
{ @Y1s$,=xB
return nSplitter; EK4d_L]I
} sBcPq SMby
V4_=<W
P9T}S
public void setNSplitter(int nCount) 6I%5Q4Ll
{ e)(wss+d7P
nSplitter = nCount; nDHTV!]<
} oH_;4QU4y
} =3L;Z[^9
=weSyZ1~
-3Hy*1A.
/* 2 B
**Utility.java p6;OL@\~
*/ ,^C--tgZJg
package NetFox; k |eBJ%
YJ\Xj56gv
/Njd[=B
public class Utility { g*_cPU0~m
VIv&ofyAR
<ZNzVnVA
public Utility() RS8Hf~0G
{ ME*LHr,
>k (C
N<XNTf
} E"5*Ei)^3
<i&_ooX
//线程睡眠 tNbN7yI
public static void sleep(int nSecond) ]@phF _
{ sG F aL
try{ ee^{hQi
Thread.sleep(nSecond); Z'.AAOG
} ;IZwTXu!S
catch(Exception e) c}2jmwq
{ T(U_
e.printStackTrace (); `~By)?cT_>
} /w}u3|L$
} t:'Mh9h7u
wY[+ZT
//日志 L6|oyf
public static void log(String sMsg) ^SF&=NpV
{ ]SLP}Jwy
System.err.println(sMsg); toBHkiuD
} &7K?w~
cWe"%I
KV0]m^@x
public static void log(int sMsg) 2*^j
{ xD~5UER
System.err.println(sMsg); YwjKAyLU
} J^Wa8Q;9lX
} [J?aD`{#O
F^];U+J
<+?7H\b
/* ]1#e#M]#
**TestMethod.java ?iWi
*/ Ju1D =b
package NetFox; @~"h62=] -
j~[z2tV
|}Nn!Sj>#;
public class TestMethod { #."-#"0
0tT(W^ho g
:&V h?
public TestMethod() ?kbiMs1;u
{ ///xx/weblogic60b2_win.exe c7x~{V8
try{ 4R1<nZ"e~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); vunHNHltW0
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); jtW!"TOY
SiteFileFetch fileFetch = new SiteFileFetch(bean); S.-TOE
fileFetch.start(); '!!CeDy
} ! |<Fo'U
catch(Exception e){e.printStackTrace ();} kuszb~`zPY
Oi8.8M
gG(fQ 89U"
} [\v}Ul
s %j_H
uxvqMgR
public static void main(String[] args) +0nJ
{ dMv=gdY
new TestMethod(); nrub*BuA
} (X\@t-8
} JfLqtXF[&"
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