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)); O1ha'@qID
} Y1'.m5E
for(int i=0;i<nEndPos.length-1;i++) I>3]4mI*a
{ 4GfLS.Ip
nEndPos = nStartPos[i+1]; /SKr.S61e
} 'f}S,i +q
nEndPos[nEndPos.length-1] = nFileLength; ]p*) PpIl
} :fYwFD( 9
} @r]s9~Lx9
48ma&f;
=qtoDe
//启动子线程 7qUtsDK
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,%'0e/
for(int i=0;i<nStartPos.length;i++) yUSB{DLpla
{ u`'z~N4}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }H#t( 9,U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #rpqt{ml
nStartPos,nEndPos,i); )ra66E
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j>Z]J'P
fileSplitterFetch.start(); `eWcp^|
} j~E +6f\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), HV9SdJOf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); SN{*:\>,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5An0DV5
nEndPos = " + nFileLength); N Sh.g#
// fileSplitterFetch[nPos.length-1].start(); B R:
r^E]GDz
mCt>s9a)H
//等待子线程结束 &o/4hnHYt
//int count = 0; (K6`nWk2
//是否结束while循环 @Y<tH,*
boolean breakWhile = false; uT/B}`md
h*KHEg"+
a-E-hX2
while(!bStop) z;C=d(|nN
{ .lBY"W&{
write_nPos(); mVK9NK
Utility.sleep(500); |3s&Y`x-D
breakWhile = true; k4$q|x7+%
KY`96~z
<VU4rk^=
for(int i=0;i<nStartPos.length;i++) y,&M\3A
{ -k <9v.:
if(!fileSplitterFetch.bDownOver) kxW>Da<6
{ kNj3!u$
breakWhile = false; i"]8Zw_D
break; S8OVG4-
} Hm VTfH'
} iL_F*iK5
if(breakWhile) ,imvA5
break; :dguQ|e
MXF"F:-Kn
H~|%vjH
//count++; ARdGh_yJ&
//if(count>4) FMdLkyK;
// siteStop(); %p2x^air
} )c*k_/4
5g1M_8e'+
K`,d$
System.err.println("文件下载结束！"); (bx\4Ws
} *sB-scD
catch(Exception e){e.printStackTrace ();} B^_Chj*m
} PGPbpl&\t
I26gGp
S[~O')
//获得文件长度 cN WcNMm
public long getFileSize() =/g$bZ
{ Ydh<TF4!
int nFileLength = -1; 9V;$v
try{ uUz`=4%A
URL url = new URL(siteInfoBean.getSSiteURL()); ! F <] T
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @ 9 {%Kn
httpConnection.setRequestProperty("User-Agent","NetFox"); 2d2@J{
|R;l5ZKvV
^Y7/Ow
int responseCode=httpConnection.getResponseCode(); }utNZhJ
if(responseCode>=400) V`\f+Uu
{ `cP'~OT
processErrorCode(responseCode); hY}/Y
return -2; //-2 represent access is error *?bk?*?s
} =kb6xmB^t
#t@x6Vt
d{yIy'+0/
String sHeader; pf8O`e,Awf
$}nh[@
'^Utbp2<
for(int i=1;;i++) R6Zj=l[
{ 8b(1ut{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !(*a+ur&i
//Utility.log(in.readLine()); 'q92E(
sHeader=httpConnection.getHeaderFieldKey(i); IE)"rTI)b
if(sHeader!=null) *NW QmC~
{ ;4G\]%c)E{
if(sHeader.equals("Content-Length")) Fi'M"^:r{
{ z]c,}Q
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Q)Iv_N/
break; icPp8EwH
} 'cZMRRc<
} =zm0w~']E!
else V3mjbH>F
break; *IWFeu7y
} r]8x;v1
} 'B3Wza.
catch(IOException e){e.printStackTrace ();} y~ _za(k
catch(Exception e){e.printStackTrace ();} q#99iiG1
JOrELrMx
5@czK*5
Utility.log(nFileLength); N^\2 _T
u m:0y,
$_RWd#Q(
return nFileLength; GsIwY {d
} (!*Xhz,(-
tL~,ZCQz
E-)VPZ1D
//保存下载信息（文件指针位置） ]3t1=+
private void write_nPos() x}?DkFuxb
{ _ktK+8*6`
try{ +UK%t>E8
output = new DataOutputStream(new FileOutputStream(tmpFile)); s:+HRJD|
output.writeInt(nStartPos.length); pw,O"6J*
for(int i=0;i<nStartPos.length;i++) ,-(T"Ph<
{ O3kg
// output.writeLong(nPos); K`QOU-M@}
output.writeLong(fileSplitterFetch.nStartPos); RpO@pd m
output.writeLong(fileSplitterFetch.nEndPos); 7R9nMGJ@
} 5: daa
output.close(); YlswSQ
} +@emX$cFV
catch(IOException e){e.printStackTrace ();} oX'0o 'c
catch(Exception e){e.printStackTrace ();} d4Co^A&
} `DLp<_z>
qH#r-
?a5h iN0
//读取保存的下载信息（文件指针位置） ic*->-!
private void read_nPos() 8!4~T,9G
{ iq"ob8.
try{ PiMKu|,3
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /&PKCtm&~
int nCount = input.readInt(); T'ED$}N>~
nStartPos = new long[nCount]; 0xJ7M.
nEndPos = new long[nCount]; /?KtXV>]
for(int i=0;i<nStartPos.length;i++) ;V_.[aX
{ 2+?T66 g
nStartPos = input.readLong(); sm 's-gD
nEndPos = input.readLong(); G2.|fp_}pG
} pheE^jUr
input.close(); GE1i+.+-.
} /g_9m
catch(IOException e){e.printStackTrace ();} -S"5{N73
catch(Exception e){e.printStackTrace ();} X E|B)Q(
} ZgV~W#t
&v^!y=Bt
U|gpCy
private void processErrorCode(int nErrorCode) M|\^UF2e
{ o#qH2)tb
System.err.println("Error Code : " + nErrorCode); CRH{E}>
} #6Jc}g<?g
x_*%*H
^SZw`]
//停止文件下载 %*wzO9w4
public void siteStop() `79[+0hL'
{ \K}-I
bStop = true; I@2uF-
for(int i=0;i<nStartPos.length;i++) pO%{'%RA
fileSplitterFetch.splitterStop(); Ve{n<{P
Cye T]y
4/S=5r}
} UMV)wy|j
} @;vNX*-J
//负责部分文件的抓取 z{9=1XY
**FileSplitterFetch.java %Y~>Jl
*/ ? ^M /[@
package NetFox; *LANGQ"2(i
&59F8JgJ
+nZUL*Ut/
import java.io.*; x^G'rF"nT
import java.net.*; 5%*w<6<_z
~9GOk;{~&
|0`hE;Kt7
public class FileSplitterFetch extends Thread { C5xag#Z1
zh\p
:0$a.8Y\++
String sURL; //File URL tz26=8
long nStartPos; //File Snippet Start Position |EKu2We*
long nEndPos; //File Snippet End Position E<tK4?i"
int nThreadID; //Thread's ID 0RUi\X4HI
boolean bDownOver = false; //Downing is over O] Y v
boolean bStop = false; //Stop identical {C3U6kKs;R
FileAccessI fileAccessI = null; //File Access interface <$%X<sDkq
-$(Jk<
jMM$d,7B
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException E@-ta):
{ bLzs?eos
this.sURL = sURL; 8WL8/
this.nStartPos = nStart; +#2)kg 9_
this.nEndPos = nEnd; ~ 3^='o
nThreadID = id; ]hA,LY f
fileAccessI = new FileAccessI(sName,nStartPos);//定位 LxLy+yC#p
} !\FkG8
+oI3I~
F]UQuOR)
public void run() %SrM|&[
{ j9d!yW
while(nStartPos < nEndPos && !bStop) >I}9LyZt
{ xl(@C*.sC1
`ltN,?/
<Mx0\b!
try{ [}OgSP9i
URL url = new URL(sURL); :_ROJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %f j+70
httpConnection.setRequestProperty("User-Agent","NetFox"); {%C*{,#+8q
String sProperty = "bytes="+nStartPos+"-"; G?AG:%H%
httpConnection.setRequestProperty("RANGE",sProperty); <A>)[u
Utility.log(sProperty); 8"%RCE
-'`TL$
\\,f{?w
InputStream input = httpConnection.getInputStream(); n`ViTwd]MQ
//logResponseHead(httpConnection); :IMdN}(L
1|{bDlmt
%<"}y$J
byte[] b = new byte[1024]; 6sJw@OaJ
int nRead; ?^i1_v7 Bi
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0V$k7H$Z
{ k'T^dY&c
nStartPos += fileAccessI.write(b,0,nRead); :Zt2'vcGpf
//if(nThreadID == 1) &;E5[jO^D
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >5hhd38
} (@r `$5D.b
F(5hmr
/P:.qtT(
Utility.log("Thread " + nThreadID + " is over!"); %c|UmKKi
bDownOver = true; b0v:12q
//nPos = fileAccessI.write (b,0,nRead); ;{#^MD MB
} 26I
catch(Exception e){e.printStackTrace ();} foRD{Hx
} Os&n
} Su8|R"qU
\25/$Ae}c
yF13Of^l./
//打印回应的头信息 :O-iykXyI
public void logResponseHead(HttpURLConnection con) :kMHRm@{
{ xYfD()w<I
for(int i=1;;i++) #m<tJnEO
{ ~g#r6pzN-
String header=con.getHeaderFieldKey(i); 4dawg8K`9
if(header!=null) #3$\Iu
//responseHeaders.put(header,httpConnection.getHeaderField(header)); izgp*M,
Utility.log(header+" : "+con.getHeaderField(header)); WIr2{+#
else 'G&{GVbXY
break; r%@Lej5+
} \f:z+F!6R
} 7ZxaPkIu&%
urBc=3Rz
rH8@69,B
public void splitterStop() B9R(&<4
{ 8uNULob
bStop = true; Jzkq)]M
} ;5_{MCPM
m)v''`9LU
"_|oWn
} j.e0;! (L}
uo\ .7[1
>Dw~POMy
/* ^3VR-u<O
**FileAccess.java wh6yPVVF/
*//文件访问(定位，写) Q=mI9
package NetFox; oA] KE"T
import java.io.*; sRSz}]
o*WY=
t.T UmJ
public class FileAccessI implements Serializable{ H}hFFI)#Oo
:bu>],d-8'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &;yH@@Z
RandomAccessFile oSavedFile; r;BT,jiX
long nPos; +mj*o(
te|?)j
IU FH:w]
public FileAccessI() throws IOException N`@NiJ(O;
{ Vd^g9
this("",0); +4;uF]T
} 5r~#0Zf*
j9Ybx#
{]_uMg#!
public FileAccessI(String sName,long nPos) throws IOException l^GP3S
{ ca i<,3H
oSavedFile = new RandomAccessFile(sName,"rw"); >r`b_K
this.nPos = nPos; L`f^y;Y.
oSavedFile.seek(nPos); >~%e$a7}+
} 'c2W}$q
qm/Q65>E
kiUGZ^k\s
public synchronized int write(byte[] b,int nStart,int nLen) 2M#M"LHo
{ 1b=lpw1}
int n = -1; 0a8/B>
try{ .2d9?p3Y
oSavedFile.write(b,nStart,nLen); O~j> ?
n = nLen; L,y6^J!
} )u))n#P
catch(IOException e) SJD@&m%?[
{ >U F
e.printStackTrace (); X%yO5c\l2
} *6HTV0jv
oFOnjK"|F
?X@fKAj
return n; ;^t{Il'j
} 21k5I #U
)`^p%k
%%(R@kh9
} oIUy-|
@lJzr3}WZ
LYlDc;<A
/* Ol4+_n8xj
**SiteInfoBean.java hig2
*/ .<kqJ|SVi
package NetFox; v<Bynd-
LC1(Xbf
ySI~{YVM
public class SiteInfoBean { Mq';S^
[+qCs7'
d)~Fmi;
private String sSiteURL; //Site's URL 7GDHz.IX
private String sFilePath; //Saved File's Path cwGbSW$t
private String sFileName; //Saved File's Name 2<M= L1\
private int nSplitter; //Count of Splited Downloading File <&)v~-&O
K~ ;45Z2
wEzKqD
public SiteInfoBean() bH"hX
{//nSplitter的缺省值为5 r|,i'T
//default value of nSplitter is 5 \U@rg4
this("","","",5); S_~z-`;h!
} y"Nsh>h
fGmT_C0t
qKJSj
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7RZh<A>m
{ p!s}=wI`
sSiteURL= sURL; :O5og[;b
sFilePath = sPath; 8i?l02
sFileName = sName; `5H$IP1XhA
this.nSplitter = nSpiltter; "s\L~R.&
41fJ%f` G
([xo9FP;
} *b];|n{
/T.KbLx~q
s|D>-
public String getSSiteURL() 3"rzb]=R
{ u :F~K
return sSiteURL; Bn!$UUC
} 29reG,>
F]9nB3:W
*3D%<kVl
public void setSSiteURL(String value) <x!GE>sf+
{ /EG~sRvl}
sSiteURL = value; `)QCn<
} h&kZjQ&
A19;1#$=
w^]6w\p
public String getSFilePath() +}-@@,
{ oTT7M`P3h
return sFilePath; +&["HoKg}&
} 5/O'R9A4
JH8zF{?
=w$}m_AM
public void setSFilePath(String value) #0Tq=:AE>
{ \o';"Q1H
sFilePath = value; Iuh/I +[7
} }mZwd_cK
'FYJMIs
kHqztg
public String getSFileName() QFIL)'K
{ M2U&?V C!
return sFileName; xai4pF-?
} 2W$cFC
TXZv2P9
gsn)Wv$h
public void setSFileName(String value) Jnv@.
{ |c`w'W?C6
sFileName = value; >,DbNmi
} (L`j0kPN
;m2<eS`o'
rSYi<ku
public int getNSplitter() BT@r!>Nl
{ #:d =)Qj0
return nSplitter; r$wxk 4%Rz
} ~gu3g^<0v
TB;o~>9U
0VK-g}"x
public void setNSplitter(int nCount) _FwK-?4E-
{ uWrQ&}@
nSplitter = nCount; XbQlHfrS
} FW.$5*f='
} EJ`T$JD
<`0h|m'U
i9=&;_z
/* 3 LdQ]S
**Utility.java ./$cMaDJ
*/ & =/
package NetFox; C XHy.&Vt
*x)8fAr
TW^/sx
public class Utility { Lq>&d,F06)
z.rh]Zq
rL5z]RY
public Utility() t5lO'Ll*Q]
{ b9XW9O`B
|g3?y/l
Q%-di=
} R-:fd!3oQ
,E.' o=Z
//线程睡眠 RNQK
public static void sleep(int nSecond) hTbI -u7BF
{ !'Q -yoHKD
try{ |A8/FU2{
Thread.sleep(nSecond); WF\)fc#;_o
} ZR\VCVH\^
catch(Exception e) 21(p|`X
{ K|oacOF9
e.printStackTrace (); 0D8K=h&e
} Y-0?a?q2Fr
} g&n)fF
FaBqj1O1
//日志 X<R?uI?L
public static void log(String sMsg) jVH|uX"M5Y
{ 0KD]j8^
System.err.println(sMsg); . <tq61
} t5[[JD1V
jP~Z`yf
rS1fK1dys
public static void log(int sMsg) *Y@nVi
{ q{ /3V
System.err.println(sMsg); [p=*u,-
} I7&_Xr
} S(mF%WJ
{hJXj,
M?/jkc.8H
/* M4WiT<|]R
**TestMethod.java mE^o-9/
*/ 4tx|=;@0
package NetFox; 0 P[RyQI
LOTP*Syjf
` \A(9u*
public class TestMethod { lHZU iB
^GBe)~MT
2!Bd2
public TestMethod() n$[f94d=
{ ///xx/weblogic60b2_win.exe DD44"w_9
try{ s[gKc'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); XW?b\!@ $
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); FW"^99mrnb
SiteFileFetch fileFetch = new SiteFileFetch(bean); "6a8s;
fileFetch.start(); W(hMft%
} vLxQ *50v$
catch(Exception e){e.printStackTrace ();} r",]Voibd
Ys!>+nL|
vS;1/->WD
} F} d
QORN9SY
r_YIpnJ
public static void main(String[] args) `HuCT6O
{ eyp,y2Tz
new TestMethod(); *.&HD6Qr
} x3rlJs`$;
} >q7BVF6V|
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