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)); @N+6qO}
} XiN@$
for(int i=0;i<nEndPos.length-1;i++) _6{XqvWqb
{ {x/)S*:Z
nEndPos = nStartPos[i+1]; J+0T8 ?A
} $ 2PpG|q
nEndPos[nEndPos.length-1] = nFileLength; !6DH6<HC
} !ZTBiC5R
} 3q:>NB<
Bq#B+JwX
>r5s>A[YC
//启动子线程 B/ACU
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; E3,Nc`'m9
for(int i=0;i<nStartPos.length;i++) f|-%.,
{ uUI@!)@2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PvqG5-L~W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ""u>5f
nStartPos,nEndPos,i); kJG0X%+w
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0N4+6k|
fileSplitterFetch.start(); m<| *
} y?yWM8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @DA.$zn&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); =/L;}m)7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $VyH2+ jC
nEndPos = " + nFileLength); V[r1bF
// fileSplitterFetch[nPos.length-1].start(); Pvu*Y0_p
CWS&f g%o{
ca!DZ%y
//等待子线程结束 4Q n5Mr@<
//int count = 0; 2g:V_%
//是否结束while循环 o<nkK+=Afm
boolean breakWhile = false; >.f'_2#Z&
v* /}s:a
`%A>{A"
while(!bStop) y9)Rl)7-:
{ -|nHwSrCZ/
write_nPos(); Iji9N!Yx
Utility.sleep(500); Q=Y1kcTOn
breakWhile = true; -/ h'uG
!Xf7RT
?PST.+l
for(int i=0;i<nStartPos.length;i++) 5t-dvYgU
{ -x0VvkHu
if(!fileSplitterFetch.bDownOver) .0f6b
{ BP`'1Ns
breakWhile = false; Fy-N U
break; OVgx2_F
} 4J6,_8`U
} %$H~
if(breakWhile) j9]H~:g$d
break; O[/l';i
|>L|7>J{<d
E{B=%ZNnm
//count++; |$aTJ9 Iq:
//if(count>4) >,s.!vpK
// siteStop(); ;^Hg\a
} &$+nuUA
dE0p>4F
WyDL ah^/
System.err.println("文件下载结束！"); n%1I}?$fO
} i%eq!q
catch(Exception e){e.printStackTrace ();} `U[s d*C"
} ?ta(`+"
ej9|Y5D"S
X9oxni#
//获得文件长度 {#X]D~;s+
public long getFileSize() .|Zt&5osI
{ A,'JmF$d
int nFileLength = -1; B>"O~ gZ{#
try{ 1hnw+T<<W
URL url = new URL(siteInfoBean.getSSiteURL()); xU_Dg56z'&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3iC$ "9!p
httpConnection.setRequestProperty("User-Agent","NetFox"); $X%'je
8#&axg?a
#\X="'/
int responseCode=httpConnection.getResponseCode(); g<&n V>wF
if(responseCode>=400) -p\uW0XA
{ N! N>/9
processErrorCode(responseCode); +{F2hEYP
return -2; //-2 represent access is error vPbmQh ex
} 3 2MdDa
bQFMg41*w7
mzkv/
String sHeader; mcB8xE
/9..hEq^
}g\1JSJ%H
for(int i=1;;i++) drc]"6 k
{ 7-u['nFJ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); quEP"
//Utility.log(in.readLine()); G^Q8B^Lg
sHeader=httpConnection.getHeaderFieldKey(i); C_~hX G
if(sHeader!=null) 8Q2qroT
{ ':jsCeSB
if(sHeader.equals("Content-Length")) @CJ`T&
{ R<GnPN:c
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); G$)f5_]7{
break; :s5wFumD
} tUPdq0%t[
} >|S&@<
else (+^z9p7/!
break; C%l+<wpXO
} E0o?rgfdq
} 9< $n'g
catch(IOException e){e.printStackTrace ();} 7eyVm;LQD
catch(Exception e){e.printStackTrace ();} 6~@S,i1
fi.[a8w:W
QSxR@hC
Utility.log(nFileLength); /\0rRT
WK<:(vu.
6pCQP c*A
return nFileLength; }KZt7)
} |)vC^=N{+
^[]@dk9
~dFdO7
//保存下载信息（文件指针位置） d@?++z
private void write_nPos() #OT8_D
{ {r,MRZaa
try{ lPywrTG0
output = new DataOutputStream(new FileOutputStream(tmpFile)); [m9Iz!E
output.writeInt(nStartPos.length); %Ct^{k~1
for(int i=0;i<nStartPos.length;i++) f*ICZM
{ Z&VH7gi
// output.writeLong(nPos); F^/1 u
output.writeLong(fileSplitterFetch.nStartPos); eM$NVpS3
output.writeLong(fileSplitterFetch.nEndPos); E9"P~ nz
} +nj 2
output.close(); 3?+CP-T-j
} 6(5YvT
catch(IOException e){e.printStackTrace ();} N#Y|MfLc
catch(Exception e){e.printStackTrace ();} `3CdW
} 4N- T=Ig
OrJuE[R.
>Yf)]e-
//读取保存的下载信息（文件指针位置） G'M;]R9EP
private void read_nPos() (5Z*m<]c
{ ~7$4w# of0
try{ _,?<r&>v6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8NJxtT~0c~
int nCount = input.readInt(); *@zh
nStartPos = new long[nCount]; +[R,wsG
nEndPos = new long[nCount]; "^UJC-
for(int i=0;i<nStartPos.length;i++) FZ0wtS2
{ ruKm_j#J
nStartPos = input.readLong(); 8`{)1.d5[
nEndPos = input.readLong(); 'kC,pN{->
} N-9Vx#i
input.close(); MN.h,^b
} Ddr.kXIpo
catch(IOException e){e.printStackTrace ();} ,_$}>MY;
catch(Exception e){e.printStackTrace ();} 4.7 PL
} y_7lSo8<
26&$vgO~:
oE H""Bd
private void processErrorCode(int nErrorCode) UCz\SZ{za
{ }^@Q9<P^E
System.err.println("Error Code : " + nErrorCode); iaAj|:
} nsM=n}$5x
iiw\
y$Rr,]L
//停止文件下载 $Sx(vq6(
public void siteStop() /~O>He
{ `Pcbc\"*y
bStop = true; 8nj^x?bn
for(int i=0;i<nStartPos.length;i++) UK7pQt}9
fileSplitterFetch.splitterStop(); p";5J+?(
'BiR ,M$mY
=Lc!L !(,b
} Hrk]6*
} OtVRhR3>
//负责部分文件的抓取 ]27
**FileSplitterFetch.java )43\qIu\
*/ Y_gMoo
package NetFox; @BfJb[A#
:< d.
I0qSx{K
import java.io.*; 0'QX*xfa>
import java.net.*; d5z=fH9
2&,jO+BqE@
tpY]Mz[J
public class FileSplitterFetch extends Thread { v><c@a=[
:]rb}1nLB
`k.Tfdu)K
String sURL; //File URL t4P`#,:8
long nStartPos; //File Snippet Start Position e2><Y<
long nEndPos; //File Snippet End Position GGQ%/i]:
int nThreadID; //Thread's ID %6%~`((4
boolean bDownOver = false; //Downing is over Pss$[ %
boolean bStop = false; //Stop identical b4R;#rm
FileAccessI fileAccessI = null; //File Access interface 3OlXi9>3
z]%c6ty
mM$|cge"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^5D%)@~
{ ..K@'*u
this.sURL = sURL; Xt.ca,`U
this.nStartPos = nStart; #hZ`r5GvTj
this.nEndPos = nEnd; 7G\a5
nThreadID = id; p=jpk@RX
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #lY_XV.
} VRs|";
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1`Ig A0V`"
public void run() Ct<]('Hm(
{ KL<,avC/
while(nStartPos < nEndPos && !bStop) Ym8 V)
{ D^Gs_z$['
l"rX'g?
:u9OD` D
try{ gr^TL1(
URL url = new URL(sURL); JE*d-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bl3?C
httpConnection.setRequestProperty("User-Agent","NetFox"); f|'0FI
String sProperty = "bytes="+nStartPos+"-"; Vm*E^ v
httpConnection.setRequestProperty("RANGE",sProperty); K0usBA
Utility.log(sProperty); )4e8LO
B6yTD7
11((b
InputStream input = httpConnection.getInputStream(); qN"Q3mU^h*
//logResponseHead(httpConnection); "OO)m](w
jAcrXB*
A`:a T{j
byte[] b = new byte[1024]; W5Uw=!LdEY
int nRead; =o5|W'>`
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) `PUGg[Zx^
{ UasU/Q <
nStartPos += fileAccessI.write(b,0,nRead); W>j@E|m$
//if(nThreadID == 1) ]<*-pRN
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,x=S)t
} -hY@r 7y
|kGQ~:k+P
aJ"m`5]=%
Utility.log("Thread " + nThreadID + " is over!"); *N&~Uq^
bDownOver = true; % aqP{mOO
//nPos = fileAccessI.write (b,0,nRead); &"?S0S>r!
} c[>xM3=e^q
catch(Exception e){e.printStackTrace ();} H:F'5Zt
} %6W%-`
} bs&>QsI?j
8Drz i!}
CUN1.i<pk8
//打印回应的头信息 1N}vz(0"
public void logResponseHead(HttpURLConnection con) )`BKEaf
{ p/U{*i]t
for(int i=1;;i++) ~Z~V:~
{ mIZ6[ ?
String header=con.getHeaderFieldKey(i); :2.<JUDM
if(header!=null) 0T7t.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Rc vp@
Utility.log(header+" : "+con.getHeaderField(header)); ij,Rq`}l
else #,9s\T
break; \c}pzBFd
} aH?+^f"D
} >r3SF3XMq
_CMNmmp`e
7Fx0#cS"\
public void splitterStop() Yi j^hs@eV
{ hXh nJ
bStop = true; DF>3)oTF
} 4a=QTq0p
aka)#0l .
FP'-=zgc
} 7^7Jh&b)/
#U(kK(uO
hv`I`[/J
/* 63i&<
**FileAccess.java 3$_JNF`
*//文件访问(定位，写) dmWCNeja.
package NetFox; aJQzM
import java.io.*; fC".K Yjp
DNr*|A2<
<aLS4
public class FileAccessI implements Serializable{ unih"};ou
7`f%?xVn0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 GC~nr-O
RandomAccessFile oSavedFile; _=cU2
long nPos; jV[;e15+
8iTB
!FwNq'Q8$
public FileAccessI() throws IOException 4f&"1:
{ ? G`6}NP
this("",0); )$h!lAo
} $J):yhFs e
)8!*,e=4
l8khu)\n4R
public FileAccessI(String sName,long nPos) throws IOException la}cGZ; p.
{ f^ja2.*%?
oSavedFile = new RandomAccessFile(sName,"rw"); a^8PB|G
this.nPos = nPos; '55G:r39
oSavedFile.seek(nPos); I~;w Q
} wn;)La
2M*i'K;;)P
58d[>0Xa[g
public synchronized int write(byte[] b,int nStart,int nLen) \wDL oR
{ r1TdjnP,2^
int n = -1; H,c`=Ii3
try{ mPhu#oK'f
oSavedFile.write(b,nStart,nLen); K9-9 c"cz
n = nLen; Cv@)tb
} n.rn+nuwv
catch(IOException e) nEUUD3a
{ SK#&%Yk
e.printStackTrace (); v[2&0&!K#
} wBvVY3VQ^
=P%&]5ts
q|:wzdmNZ
return n; $H)QUFyC
} t.dr<
|dz"uIrT
X5\xq+Ih
} x0b=r!Duu
zO---}[9a
tXqX[Td`0g
/* 2n$Wey[
**SiteInfoBean.java peF)U !`D
*/ 1yZA_x15:
package NetFox; L$i:~6
*:Rs\QH
[}M!ez
public class SiteInfoBean { q-+:1E
$4^SWT.
%ioVNbrR7
private String sSiteURL; //Site's URL S@Rd>4
private String sFilePath; //Saved File's Path KzP{bK5/
private String sFileName; //Saved File's Name -|Zzs4bx
private int nSplitter; //Count of Splited Downloading File ALy7D*Z]w
/`l;u7RD
}W'4(V;:
public SiteInfoBean() 2lO(f+
{//nSplitter的缺省值为5 ^86M94k
//default value of nSplitter is 5 f9 \$,7F
this("","","",5); YrJUs]A
} !:m.-TE
aG83@ABx
"a=Hr4C*r
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "p*'HQ
{ tfN[-3)Z
sSiteURL= sURL; p20JUzy
sFilePath = sPath; Scx!h.\5
sFileName = sName; 'Y#'ozSQv
this.nSplitter = nSpiltter; m$_b\^we
e`S\-t?Z
v2E<~/|
} -iS^VzI|I
tj'~RQvO
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public String getSSiteURL() -2; 6Pwmv
{ 6^WNwe\
return sSiteURL; bY2R/FNL=
} vUVFW'-
y^,QM[&
'.1P\>x!]
public void setSSiteURL(String value) 4"k&9+>
{ ~f(5l.
sSiteURL = value; `hZh}K^
} L7Hv)
H7GI`3o
ZX` \so,&,
public String getSFilePath() DH yv^
{ 2t9UJu4
return sFilePath; $Yt|XT+!&
} @t~y9UfF
7;o:r$08&}
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public void setSFilePath(String value) 60vmjmXl
{ E<Zf!!3
sFilePath = value; jkx>o?s)z
} jel:oy|_
Ig t*8px
X'jyR:ut#
public String getSFileName() <@"rI>=
{ %*}rLn"?
return sFileName; Yr/$92(
} T2MC`s|`
7%i'F=LzT
hqvhnqQk
public void setSFileName(String value) V!+iq*Z|=
{ 3"7Q[9Oj
sFileName = value; ?!P0UTe~
} G;}WZy
hHN[K
L@{'J
public int getNSplitter() s|e.mZk/
{ 3e&+[j
return nSplitter; <rj'xv
} 7DJEx~"!2-
5[Vr {^)
SK\@w9#&$
public void setNSplitter(int nCount) OUi;f_*[r
{ U L $!
nSplitter = nCount; UeO/<ml3>J
} VKDOM0{V
} P}}G9^
d\JaYizp
\{@m
/* Wp>t\S~N
**Utility.java 'vd&r@N
*/ |@u2/U9
package NetFox; {&n- @$?
zsXgpnlHT
Pp-N2t86#2
public class Utility { 3p=Xv%xd
E:x@O8F
g:M;S"U3*Y
public Utility() K<e #y!
{ yMz#e0k
R%WY!I8C
fWmc$r5n](
} ,2fi`9=\
wuH*a3(
//线程睡眠 +Ww] %`_
public static void sleep(int nSecond) MW7~=T
{ * @4@eQF
try{ -`PziGl@<
Thread.sleep(nSecond); H%O\4V2s
} Y1-dpML
catch(Exception e) [7I bT:ph
{ [f_^BU&
e.printStackTrace (); 1?Y>Xz
} )XDBK*!
} YRlfU5
Ic2?1<IZA
//日志 rE+B}O
public static void log(String sMsg) ;qgo=
{ 2R&\qZ<
System.err.println(sMsg); 7#R)+
} l;iU9<~
r%.k,FzGZY
0V1GX~2
public static void log(int sMsg) Mk}T
{ 7 ~~ug
System.err.println(sMsg); _"1RidhH
} [<#jK}g
} Op%OQ14$
xJCxzJ
:*}Q/]N
/* =x8[%+
**TestMethod.java 61S;M8tNv
*/ Y"mFUW4
package NetFox; Keh=>K)T
>5-1?vi
iwK.*07+
public class TestMethod { <gF]9%2E
k_7m[o
;7P'>j1?U
public TestMethod() )dkU4]
{ ///xx/weblogic60b2_win.exe VmqJMU>.
try{ qdix@@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); CeYhn\m5K0
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 4-yK!LR
SiteFileFetch fileFetch = new SiteFileFetch(bean); CVfV
fileFetch.start(); e34>q:#5l
} :0r,.)
catch(Exception e){e.printStackTrace ();} e=0]8l>\V
%y RGN
XRV]u|w=g
} CPOHqK`k
XQy`5iv
i(j/C
public static void main(String[] args) ]{1{XIF
{ `MU~N_
new TestMethod(); $,}jz.R@
} R(wUu#n$
} OXEEpoU?V
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