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)); jc${.?m
} ._8xY$l$
for(int i=0;i<nEndPos.length-1;i++) dM$N1DB{U+
{ bbfDt^
nEndPos = nStartPos[i+1]; N |OMj%Uk
} 7KvXTrN!9
nEndPos[nEndPos.length-1] = nFileLength; CsJ)Z%4_
} -d$8WSI8
} MLkL.1eGSb
>cGh|_9
P-/XYZ]`
//启动子线程 Z?!JV_K
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {m?K2]](
for(int i=0;i<nStartPos.length;i++) K> c8r8!
{ Z/XM`Cy
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (#fm (@T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), r78u=r
nStartPos,nEndPos,i); }:,o Y<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "R@$Wu53|
fileSplitterFetch.start(); m_{%tU;N
} A^}i^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R@)'Bs
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3K=q)|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", x.0k%H
nEndPos = " + nFileLength); B[) [fE
// fileSplitterFetch[nPos.length-1].start(); VEFwqB1l
bLU^1S8Z
FYx `o\
//等待子线程结束 ~zXG<}n
//int count = 0; UFzM#
//是否结束while循环 <3i4NXnL2
boolean breakWhile = false; LUe>)eqw
~!a~C~_
2b6? 9FX*
while(!bStop) iBGSBSeL&
{ 3p?<iVE
write_nPos(); =j'J !M
Utility.sleep(500); r`&2-]
breakWhile = true; h"RP>fZt
zIAu3
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for(int i=0;i<nStartPos.length;i++) X/- W8
{ fD3jwPL
if(!fileSplitterFetch.bDownOver) ,ZzB#\
{ vp )}/&/
breakWhile = false; AF9[2AH=Y
break; Mp^OL7p^^
} pJ2:` f<;
} Z1)jRE2dl
if(breakWhile) v&[X&Hu[
break; F#!@}K8
gL[1wM%?
XEvGhy#
//count++; ;Sx'O
//if(count>4) Dr8WV\4@
// siteStop(); v -|P_O&z
} %-1BA*J`|
L5V'Sr
S|RpA'n
System.err.println("文件下载结束！"); A4 A6F<
} ] dm1Qm
catch(Exception e){e.printStackTrace ();} 5vUz
} |1<]o;:
xzMeKC`
D^N#E>,
//获得文件长度 K#JabT
public long getFileSize() Cu ['&_@
{ dIBKE0`
int nFileLength = -1; jE?\Yv3
try{ p,[XT`q^
URL url = new URL(siteInfoBean.getSSiteURL()); (^s&M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m p|20`go
httpConnection.setRequestProperty("User-Agent","NetFox"); /A[oj2un
*D09P%
HX /GLnY/X
int responseCode=httpConnection.getResponseCode(); |&0"N[t
if(responseCode>=400) .%J?T5D
{ xnRp/I
processErrorCode(responseCode); T~wZ
return -2; //-2 represent access is error Dh!iY0Lz
} k+7M|t.?4
R$T[%AGZ.
Wd^F%)(
String sHeader; Bah.\ZsYQP
; $ ?jR c
oM18aR&
for(int i=1;;i++) #iRyjD
{ U&]p!DV&;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +LI*!(T|lm
//Utility.log(in.readLine()); 5E\<r/FeJ
sHeader=httpConnection.getHeaderFieldKey(i); zT4ulXN
if(sHeader!=null) 9znx1AsN
{ 8}pcanPg
if(sHeader.equals("Content-Length")) ?5r2j3mqgv
{ 9pl_V WrQ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4I:JaRT d
break; O yH!V&w
} @F3-Ugm
} Qa7S'(
else cyHaku+
break; WFeMr%Zqh>
} ].<sAmL^
} #<tWYE
catch(IOException e){e.printStackTrace ();} jL7MmR#y5"
catch(Exception e){e.printStackTrace ();} $!l2=^\3
eUKl Co
$)TF,-#x
Utility.log(nFileLength); ExOB P
]"7DV3_
u7Y'3x,`
return nFileLength; Io4:$w
} /|u]Y/ *
}x#P<d(
?D~SHcBaN
//保存下载信息（文件指针位置） rlO%%Qn`
private void write_nPos() 49J+&G?)j
{ mBpsgm:g^
try{ 4_m /_Z0x
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]|$$:e^U9
output.writeInt(nStartPos.length); \_I)loPc8
for(int i=0;i<nStartPos.length;i++) z?t(+^
{ O[hbu![
// output.writeLong(nPos); WKrZTPD'm
output.writeLong(fileSplitterFetch.nStartPos); X%9xuc
output.writeLong(fileSplitterFetch.nEndPos); Mly z><
} |jaY[_.@
output.close(); n;k97>m${x
} 9+is?Pj
catch(IOException e){e.printStackTrace ();} [P&,}o)+E0
catch(Exception e){e.printStackTrace ();} ~4~Tcn
} gh #w%g1g
y~A7pzBZ=
l-^XW?CfL
//读取保存的下载信息（文件指针位置） H;t8(-F@'
private void read_nPos() 't]EkH]BC
{ da?th
try{ o4[2`mT
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @X6#$ex
int nCount = input.readInt(); H+#wj|,+\
nStartPos = new long[nCount]; @aD~YtL"n
nEndPos = new long[nCount]; a]wcA
for(int i=0;i<nStartPos.length;i++) \]`(xxt1
{ Tx!m6B`Y
nStartPos = input.readLong(); +|"n4iZ!)
nEndPos = input.readLong(); DN8pJa
} &!YH"{b
input.close(); eRx[&-c
} $W_o$'crW
catch(IOException e){e.printStackTrace ();} )p^jsv.
catch(Exception e){e.printStackTrace ();} 1uge>o&
} UWWD8~:
_g`0td>N
dzv,)X
private void processErrorCode(int nErrorCode) ~"rwP=<}
{ e>zk3\D!
System.err.println("Error Code : " + nErrorCode); X.AOp
} q'V{vFfY%
ot+~|Dl
*1)NABp6D
//停止文件下载 [rQ(ae
public void siteStop() wIR[2&b
{ "xc*A&Sg
bStop = true; gAUQQ
for(int i=0;i<nStartPos.length;i++) 1707
fileSplitterFetch.splitterStop(); Z8dN0AqZ
]>4Qs
:XQ
} 'lRHdD}s
} _TN$c
//负责部分文件的抓取 +@)$l+kk9
**FileSplitterFetch.java yzNX2u1
*/ L{0OMyUA
package NetFox; S5 nw
IM5^E#-g7
a=B0ytNm
import java.io.*; 5NF&LM;i(
import java.net.*; \HQb#f,
*-!ndbf
WfbNar[
public class FileSplitterFetch extends Thread { W>|b98NPu
3Q~&xNf
l`%} {3r9
String sURL; //File URL gcCYXPZp
long nStartPos; //File Snippet Start Position x[>_I1TJ
long nEndPos; //File Snippet End Position )B&<Bk+
int nThreadID; //Thread's ID rH:X/i;D
boolean bDownOver = false; //Downing is over v8k^=A:
boolean bStop = false; //Stop identical *4^]?Y\*
FileAccessI fileAccessI = null; //File Access interface [<fLPa
0o=)&%G
Z%9^6kdY
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException dVt@D&
{ +95dz?~
this.sURL = sURL; %y7wF'_Y
this.nStartPos = nStart; $)7f%II
this.nEndPos = nEnd; h-rj
nThreadID = id; s]%!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 I2lZ>3X{
} P~ZV:Of
h%^kA@3F
Lpbn@y26<
public void run() RMt vEa
{ )Qj9kJq
while(nStartPos < nEndPos && !bStop) Q0; gF?
{ 4$2T zJE
99>yaW
coVT+we
try{ F}.TT=((8
URL url = new URL(sURL); 2_\|>g|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); U`p<lxRgQ
httpConnection.setRequestProperty("User-Agent","NetFox"); _w/N[E
String sProperty = "bytes="+nStartPos+"-"; `LU,uz
httpConnection.setRequestProperty("RANGE",sProperty); l<:E+lU
Utility.log(sProperty); JI,hy <3l0
.*f4e3
kpw4Mq@
InputStream input = httpConnection.getInputStream(); W!B4<'Fjc
//logResponseHead(httpConnection); wP':B AQ4U
S^VV^O5 ^
a[cH@7W.#
byte[] b = new byte[1024]; E=*Q\3G~
int nRead; X/7_mU>aKT
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3M*[a~
{ *K.7Zf0
nStartPos += fileAccessI.write(b,0,nRead); [f(^vlK
//if(nThreadID == 1) ~wg^>!E
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BF[?* b
} vm^# aoDB
,:4w$!;
uBkny;
Utility.log("Thread " + nThreadID + " is over!"); 7=*k@9
bDownOver = true; TXl9c6
//nPos = fileAccessI.write (b,0,nRead); c]R![sa
} 3&Rqz9W
catch(Exception e){e.printStackTrace ();} B[|/wHMsT}
} $K fk=@
} !jq6cND
3i}B\ {
|3@Pt>Ikl
//打印回应的头信息 _-\{kJ
public void logResponseHead(HttpURLConnection con) &LQab>{*K
{ TC#B^m`'p
for(int i=1;;i++) 2U+p@}cQUA
{ B"zg85 e
String header=con.getHeaderFieldKey(i); 3 v$4LY
if(header!=null) #}yFHM?i
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 7 ~8Fs@
Utility.log(header+" : "+con.getHeaderField(header)); u.Yb#?
else X*"O'XCA
break; bd*(]S9d
} O~OWRJ@p
} l>?vjy65
DkKD~
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public void splitterStop() 9cj-v}5j
{ HKw:fGt/o^
bStop = true; F|Ihq^q
} HZ=yfJs nc
g|_*(=Q
*bSG48W("
} ~At.V+
'oL[rO~j
Li^!OHro.
/* c6)zx b
**FileAccess.java o:\a
*//文件访问(定位，写) O^%ace1
package NetFox; /k"P4\P`+Q
import java.io.*; K!gFD
s7} )4.vO
{~h\;>
public class FileAccessI implements Serializable{ g(H3arb&
vJUB;hD
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 NmF2E+'
RandomAccessFile oSavedFile; Z+4Oaf!
long nPos; FCJ(D!
t O>qd#I
Lpf=VyqC
public FileAccessI() throws IOException ?EAqv]
{ (Z +C
this("",0); ,SwaDWNO
} <);u]0
Ec 7M'~1
)yZE>>3-
public FileAccessI(String sName,long nPos) throws IOException QjU"|$
{ }>U03aa!
oSavedFile = new RandomAccessFile(sName,"rw"); "iGc'?/+
this.nPos = nPos; ;gV8f{X{Z
oSavedFile.seek(nPos); 9E?>B3t^
} \ y",Qq?
oP 0j>i,"&
)~(_[='
public synchronized int write(byte[] b,int nStart,int nLen) yqI|BF`
{ ~A4WuA
int n = -1; 0eP~F2<bC
try{ uu.Nq*3
oSavedFile.write(b,nStart,nLen); B ;$8<
n = nLen; &,7(Wab
} m 0PF"(
catch(IOException e) oX,M;;Yq
{ ^umAfk5r?H
e.printStackTrace (); rnE'gH(V'
} B=|sLs`I
'WCTjTob/
{!h[@f4
return n; >,vuC4v-
} .R5z>:A
j(JI$
Y,~]ecI
} <~w#sIh
Xii#Qtd.
MsQS{ok+
/* LJ3UB
**SiteInfoBean.java WpZ^R;eK
*/ DlI|~
package NetFox; kw'D2692
iSlVe~ef
b\Ub<pE
public class SiteInfoBean { C:{'0m*jKs
c3dZ1v
+i =78
private String sSiteURL; //Site's URL m(Ynl=c
private String sFilePath; //Saved File's Path [4yQ-L)]e
private String sFileName; //Saved File's Name a\E]ueVD2j
private int nSplitter; //Count of Splited Downloading File _Ar,]v
H#E0S>Jw|
Nl _Jp:8s
public SiteInfoBean() lc7]=,qyF
{//nSplitter的缺省值为5 |0-L08DW
//default value of nSplitter is 5 $49tV?q5
this("","","",5); } _z~:{Y
} !ZW0yCwLQ
nE84W$\
[bXZPIz;j
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) >2/zL.O
{ mgWtjV 8
sSiteURL= sURL; jXf-+;ZQ
sFilePath = sPath; 9nE%r\H
sFileName = sName; 5hMiCod
this.nSplitter = nSpiltter; Q23y.^W%c
.O^|MhBJu
iy9]Y5b
} +qec>ALAg
x;Q2/YZ#
uItKsu
public String getSSiteURL() hlZjk0ez
{ Tw5BvB1
return sSiteURL; H@:@zD!G[
} ;21JM2JI8
\Wk$>?+#@
JV>OmUAk
public void setSSiteURL(String value) Pt+_0OsR
{ kn.z8%^(
sSiteURL = value; M> <
} V*~5*OwB
tG-MC&;=
2RCnk&u
public String getSFilePath() S0`*
{ MNzq}(p
return sFilePath; ",m5}mk:4
} xT/&'$@{)
W+E2({
&AVi4zV
public void setSFilePath(String value) qz&)|~,\C
{ 3^Y-P8.zdB
sFilePath = value; $B2@mC([S
} RZZB?vx
P}jr 8Z
|Th{*IJ<,
public String getSFileName() gnGw7V
{ ~08v]j q
return sFileName; `*a,8M%
} i]v!o$7
.uP$M(?j
o&zV8DE_v
public void setSFileName(String value) jX%Q
{ .+<K-'&=
sFileName = value; {`LV{!
} f8lww)^,v
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79v&6Io
public int getNSplitter() K5$ y
{ !FO)||'[
return nSplitter; sIpK@BQ'
} !ktr|9Bl
~>n<b1}W
=6$(m}(74
public void setNSplitter(int nCount) bQ%^l#H_n'
{ `W9_LROD
nSplitter = nCount; `6/7},"9t
} fCKcv |
} &V"&SV>}
n!p&.Mt
?S_S.Bd
/* R~i<*
**Utility.java <+a\'Xc
*/ e/6oC~#]
package NetFox; 3-05y!vbcE
+vP1DXtj(
w%ForDB>P
public class Utility { epnDvz\
O tr@jgw
]q j%6tz
public Utility() L`\ILJz
{ .XmD[=
~4M]SX1z
&e(de$}xt
} _heQ|'(
Wq4?`{
//线程睡眠 jHd~yCq
public static void sleep(int nSecond) pr2d}~q4{
{ AXyuXB
try{ SG~R!kN}Q
Thread.sleep(nSecond); fKfi
} ,O2F}5|;
catch(Exception e) C}!|K0t?
{ [8"nRlXH
e.printStackTrace (); V;m3=k0U
} ^^Ius ]
} +m1edPA[
O@[q./VV,
//日志 z|9 ^T@)
public static void log(String sMsg) T<OLfuV
{ >4Lb+]
System.err.println(sMsg); V{npK(
} ?$ 3=m)s
b7$?'neH/.
lBCM;#P
public static void log(int sMsg) &(K*TB|Om
{ f /jN$p
System.err.println(sMsg); Gqs8$[o
} SbB5J> >7J
} Z'EZPuZ!'
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R\<^A~(Gl
/* k: {$M yK
**TestMethod.java M! s&<Bi
*/ =$m|M m[a
package NetFox; I=1tf;Bsi
6} 9A0
O:#to
public class TestMethod { m,pDjf
$oNkE
!v^D j']
public TestMethod() K1Tzy=Z9j
{ ///xx/weblogic60b2_win.exe os>|LPv4
try{ 9TF[uC)-2
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); QoqdPk#1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); htaB!Q?V
SiteFileFetch fileFetch = new SiteFileFetch(bean); k,r\^1h
fileFetch.start(); MW p^.
} M?_VYK
catch(Exception e){e.printStackTrace ();} 03MB,
ZXco5,1
k -SUp8}g
} Dr;@)
xT@\FwPr
4Ld0AApncy
public static void main(String[] args) 5L4~7/kj
{ 6rRPqO j
new TestMethod(); jtZ@`io
} 40Du*5M
} oV*3Mec
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