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)); vF;%#P
} ;ePmN|rq;
for(int i=0;i<nEndPos.length-1;i++) *"Ipu"G5?
{ dQt*/]{q
nEndPos = nStartPos[i+1]; LRv-q{jP;
} XH0R:+s
nEndPos[nEndPos.length-1] = nFileLength; ?/~7\ '|Z
} xU^Flw,4
} uM0z%z5b
F[c;iM(^
n}yqpW!%n
//启动子线程 q"A(l
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;#!`cgAh
for(int i=0;i<nStartPos.length;i++) lFD$Mc
{ ~'HwNzDQc
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ajhrsa\~a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), gBq,So
nStartPos,nEndPos,i); 8lt P)K4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2|#3rF
fileSplitterFetch.start(); ue$\i=jw
} .c+RFX@0
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fdN-Zq@'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); N@^?J@#V
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Z| +/Wl-h
nEndPos = " + nFileLength); Ne.W-,X^cL
// fileSplitterFetch[nPos.length-1].start(); }yU,_:
_#e='~;
bI=\n)sEz
//等待子线程结束 z1F[okLA
//int count = 0; S~}?6/G.
//是否结束while循环 &S<tX]v
boolean breakWhile = false; Vrf` :%
d;(L@9HHD
Ni{(=&*=
while(!bStop) PS@` =Z
{ |]]Xee]
write_nPos(); a)[XJLCQ
Utility.sleep(500); NQ{ XIN~
breakWhile = true; `96:Z-!}
t4UKG&[a
iR(A^
for(int i=0;i<nStartPos.length;i++) {`~{%2ayq7
{ ts%@1Y?
if(!fileSplitterFetch.bDownOver) S0g5Ym ia
{ 2[Q*?N
breakWhile = false; wI}5[m
break; E'&UWDh
} 7##nY3",^
} ^`\c;!)F<
if(breakWhile) IX^k<Jqr
break; Jnm{i|6N
f 7et
7^Jszd:c08
//count++; }jfU qqFd
//if(count>4) MlsF?"H p
// siteStop(); 9 YU7R)
} 7 4aap2^
T8ZBQ;o
FymA_Eq
System.err.println("文件下载结束！"); OgS6#X
} qw0tw2|
catch(Exception e){e.printStackTrace ();} z(>{"t<C
} #v')iR"
{`KgyCW:
pR&cdORsP
//获得文件长度 3.Qf^p
public long getFileSize() <h U ZD;
{ RoLUPy9U
int nFileLength = -1; bP Er+?fu
try{ * C~
URL url = new URL(siteInfoBean.getSSiteURL()); 23y7l=.b/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); djPr 4Nog
httpConnection.setRequestProperty("User-Agent","NetFox"); v(=fV/
rc*&K#? B
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int responseCode=httpConnection.getResponseCode(); 4G@vO{$
if(responseCode>=400) zY\v|l<T
{ Q]w;o&eo
processErrorCode(responseCode); fmA&1u/xMs
return -2; //-2 represent access is error ,^,Vq]$3
} ^;NM'Z
1B6Go
+fAAkO*GP
String sHeader; dj?.Hc7od
u-pE ;|
A86#7
for(int i=1;;i++) |>A1J:
{ u$&7fmZ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); aAwnkQ$
//Utility.log(in.readLine()); }o=R7n%
sHeader=httpConnection.getHeaderFieldKey(i); Gc4N)oq)}b
if(sHeader!=null) =@binTC4
{ cIja^xD
if(sHeader.equals("Content-Length")) 9 o-T#~i
{ 1F/`*z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); gUL`)t\}*
break; ePIBg(
} =a?l@dI]
} {.H}+@0
else |vTirZP
break; .-`7Av+7
} K,|Gtaa~
} s3_i5,y
catch(IOException e){e.printStackTrace ();} Z=R>7~H
catch(Exception e){e.printStackTrace ();} (~}yt.7K
20zIO.&o
B HoZ}1_
Utility.log(nFileLength); %9-).k
=NF},j"
>efYpd#^
return nFileLength; //Hn[wEOh
} -YA1Uk
Kdx?s;i
,, ]y 8P
//保存下载信息（文件指针位置） tV*g1)'zX
private void write_nPos() }.o rfW
{ zL3~,z/o
try{ %nF6n:|:
output = new DataOutputStream(new FileOutputStream(tmpFile)); \[]36|$LS
output.writeInt(nStartPos.length); :8E(pq|1PB
for(int i=0;i<nStartPos.length;i++) 5U3="L
{ k2<VUeW5
// output.writeLong(nPos); \ zhT1#O
output.writeLong(fileSplitterFetch.nStartPos); H]UM2.
output.writeLong(fileSplitterFetch.nEndPos); x~j%
} \P}~ICZA
output.close(); vsqfvx
} "]*0)h_
catch(IOException e){e.printStackTrace ();} ( y2%G=.j
catch(Exception e){e.printStackTrace ();} `"zX<
} eO(VSjo'`
1U@qRU
+To{Tm-
//读取保存的下载信息（文件指针位置） sA3 4`ZAa
private void read_nPos() D gY2:&0
{ lb{*,S
try{ N:d`L+tcc
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); GLnj& Ve
int nCount = input.readInt(); %OfaBv&
nStartPos = new long[nCount]; w;}P<K
nEndPos = new long[nCount]; rbO9NRg>
for(int i=0;i<nStartPos.length;i++) 9"=:\PE
{ 46Nl];g1`
nStartPos = input.readLong(); *1ku2e]z
nEndPos = input.readLong(); #kA/,qyM
} IA$:r@QNx8
input.close(); opte)=]J
} }j+ZF'#
catch(IOException e){e.printStackTrace ();} iZgv VH
catch(Exception e){e.printStackTrace ();} BGLJ>zkq
} `cy_@Z5A
+7^%fX;3pW
=MB[v/M59w
private void processErrorCode(int nErrorCode) mAk)9`f/
{ >e=tem~/
System.err.println("Error Code : " + nErrorCode); 6Nj\N oS
} ^Ml)g=Fq
(t>BO`,
jNaK]
//停止文件下载 $MfHA~^
public void siteStop() S,n*1&ogj
{ G9N6iKP!
bStop = true; o" &7$pAh
for(int i=0;i<nStartPos.length;i++) XlV#)JX
fileSplitterFetch.splitterStop(); lDCoYX_
_j}|R(s*+V
vtCt6M
} vbmi_[,U
} <^ @1wg
//负责部分文件的抓取 la</IpC
**FileSplitterFetch.java ,wlFn
*/ XcR2]\
package NetFox; (O\5gAx
zy
$FNj>1
import java.io.*; 8}XtVF;
import java.net.*; Z8z.Xn
Wf-i)oc4I
9K@`n:Rw
public class FileSplitterFetch extends Thread { +Z/*=;
Cc$!TZq=
;R@zf1UYA
String sURL; //File URL sn@gchO9s
long nStartPos; //File Snippet Start Position r[q-O&2&
long nEndPos; //File Snippet End Position QPg QM6
int nThreadID; //Thread's ID O:{I9V-=>s
boolean bDownOver = false; //Downing is over k_ UY^vz.
boolean bStop = false; //Stop identical Ra%RcUf~sh
FileAccessI fileAccessI = null; //File Access interface [ZZ~^U5
W[AX?
8jMw7ti
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %qV=PC
{ 4sP0oe[h
this.sURL = sURL; PL@hsZty~c
this.nStartPos = nStart; vCb3Ra~L`
this.nEndPos = nEnd; )%-FnW
nThreadID = id; =XzrmPu
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \v)Dy)Vhg2
} QpBgG~h"
&;&i#ZO
(]w_}E]N
public void run() Dwj!B;AZ_
{ "|{NRIE
while(nStartPos < nEndPos && !bStop) (Dlh;Ic r9
{ $.a<b^.Xi
o:.={)rX
5@%$M$E
try{ P%8 Gaa=
URL url = new URL(sURL); sG=D(n1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?w#V<3=
httpConnection.setRequestProperty("User-Agent","NetFox"); ^vn8s~#
String sProperty = "bytes="+nStartPos+"-"; yS[:C 2v
httpConnection.setRequestProperty("RANGE",sProperty); 0BMKwZg
Utility.log(sProperty); sX.L
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F=7X,hK
InputStream input = httpConnection.getInputStream(); zflq|dW
//logResponseHead(httpConnection); ^HgQ"dD <
, ;W6wj
q6bi{L@/R
byte[] b = new byte[1024]; f=+|e"i#p
int nRead; r{!]` '8
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) B8F.}M-!
{ |L}zB,
nStartPos += fileAccessI.write(b,0,nRead); [<\k
//if(nThreadID == 1) 12`q9Io"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c@wSv2o$
} .vE=527g)
^I4'7]n-
#` Q3Z}C
Utility.log("Thread " + nThreadID + " is over!"); Jz&a9
bDownOver = true; Cc/h|4
//nPos = fileAccessI.write (b,0,nRead); [=7=zV;}4
} 2BZYC5jy
catch(Exception e){e.printStackTrace ();} sD H^l)4h
} /2N'SOX
} G0oY`WXOB
4wjy)VD_
)h6hN"#V5
//打印回应的头信息 gHdNqOy c
public void logResponseHead(HttpURLConnection con) UCG8=+t5T
{ M<s16
for(int i=1;;i++) a"SH_+T{
{ AFE6@/'
String header=con.getHeaderFieldKey(i); i8iv{e2
if(header!=null) )hs"P%Zg
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;\ ^'}S|3Z
Utility.log(header+" : "+con.getHeaderField(header)); Jmrs@
else 8mjPa^A
break; 3#N'nhUzA
} 1/X@~
} r<VZEbm)
a~q_2S]h
5$f vI#NO<
public void splitterStop() Uc%n{ a-a
{ ,5!&}
bStop = true; +`tl<rg;
} 4<}!+X7m
> %h7)}U
% `Q[?(z
} c%y(Z5
z"#iG&>a,
)3K#${p
/* .c__<I<G<
**FileAccess.java wJyrF
*//文件访问(定位，写) tpu2e*n-|
package NetFox; URU,&gy=
import java.io.*; `_%UK=m
sB!#`kh
e_RLKFv7
public class FileAccessI implements Serializable{ }L mhM
#&zM.O1Q
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~o{GQ>
RandomAccessFile oSavedFile; .#^ta9^t7
long nPos; & -r^Q
N>ncv
e&~vO| 3w%
public FileAccessI() throws IOException LGnb"ZN
{ )/HbmtXqI
this("",0); eTg8I/)%B
} "/e_[_j
R[_Q}W'HG
(=A61]yB
public FileAccessI(String sName,long nPos) throws IOException #(@!:f1
{ G47(LE"2b
oSavedFile = new RandomAccessFile(sName,"rw"); !8g419Yg
this.nPos = nPos; hcn$uyP
oSavedFile.seek(nPos); ?^Gi;d5
} 9S'u1%
6U.A/8z
OaTnQ|*
public synchronized int write(byte[] b,int nStart,int nLen) G5WQTMzf&
{ d]A.=NAc
int n = -1; PP*6nW8
try{ x[?N[>uw
oSavedFile.write(b,nStart,nLen); [U5@m]>^
n = nLen; 4X-"yQ<U
} CdBpz/
catch(IOException e) vCvjb\S
{ ak,KHA6u
e.printStackTrace (); m^k$Z0
} oX=dJJE
v~8CpC
8F>u6Y[P
return n; (Q5rOrA"
} .7K)'
&9Y ^/W
<`$svM
} mpr_AL!ZO~
rn$G.SMgz
Cn"_x
/* 1Kjqs)p^
**SiteInfoBean.java ]I,(^Xq3a(
*/ V0)bPcS/
package NetFox; ^C=dq(i=[
Vc[aNpE
3_bE12
public class SiteInfoBean { ZLjEH7
SFu]*II;{
FR9w0{o
private String sSiteURL; //Site's URL L@5sY0 M
private String sFilePath; //Saved File's Path }SfS\b{|~
private String sFileName; //Saved File's Name ,?>{M
private int nSplitter; //Count of Splited Downloading File LC1WVK/
zqHG2:MN"
OV G|WC
public SiteInfoBean() ^4b;rLfk@
{//nSplitter的缺省值为5 -9] ucmN
//default value of nSplitter is 5 nND; lVQSO
this("","","",5); Z~0TO-Q
} `uKsFXM
vjL +fH<0:
6"Ze%:AZZ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) F9} zt 9
{ lw]uH<v
sSiteURL= sURL; eo@kn yA<&
sFilePath = sPath; 5cvvdO*C0
sFileName = sName; H#S`m
this.nSplitter = nSpiltter; Y\,aJL$
eJ*u]GH U
t$Bu<frQ
} q+znb'i-x
8(Cs<C!
XS}-@5TI
public String getSSiteURL() 216`rQ}z
{ 2Z-[x9t
return sSiteURL; `fuQt4
} YQ$LU\:
)3 I~6ar
O#<F"e;$
public void setSSiteURL(String value) A`--*$8\
{ +CVB[r#hu
sSiteURL = value; M}! qH.W
} n^q%_60H
qyBC1an5,
{wDq*va
public String getSFilePath() +/[L-&,
{ x?UAj8z6
return sFilePath; {?;qy\m]o
} `;=-71Gn~
"38L ,PW0Z
28LBvJVq@
public void setSFilePath(String value) ~<.{z]*O
{ /-knqv
sFilePath = value; 6HguZ_jC
} soRYM
}[{9u#@#
O14\_eAu6
public String getSFileName() A<] $[2qPj
{ ?y]R /?
return sFileName; i[?VF\Y(
} nC%<BatQ
_!_^B
'yosDT2{#
public void setSFileName(String value) Hd\.,2a"
{ f}~=C2R1<!
sFileName = value; Q#X'.](1
} <O1os"w
V|hwT^h
3RX9LJGX
public int getNSplitter() 0h~{K
{ !{4'=+
return nSplitter; )7{r8a
} pw&k0?K#
ymp ik.'
.l hS
public void setNSplitter(int nCount) ,1g_{dMx
{ ?@z/#3b
nSplitter = nCount; =:Yrb2gP_\
} VP~(;H5%
} !7f,gvk
mrq,kwM
_s+G02/q1
/* OkAgO3>Y/
**Utility.java ^D1gcI
*/ }$'XV.
package NetFox; GKbbwT0T|
@tJ4^<`P{
')}itS8
public class Utility { {+ Ibi{
0~EGrEt
s3T7M:DM4
public Utility() [K@(,/$
{ c|d,:u#
'7pzw>E=:
RH:vd|q+
} o*artMkG
v k=|TE
//线程睡眠 oeZUd}P
public static void sleep(int nSecond) HYmUD74FR
{ t`'jr=e,~
try{ P^# 4m
Thread.sleep(nSecond); Y]*&\Ex"\
} A|,qjiEJCc
catch(Exception e) +~BP~
{ 7x=4P|(\}
e.printStackTrace (); @)x*62r+
} ,a?oGi
} aNs8T`
j74hWz+p4
//日志 Q% d1O
public static void log(String sMsg) m[(_fOd
{ kh{3s:RQfC
System.err.println(sMsg); C=|8C70[%N
} MRw4?HqB
?:M4GY"gV
[KFCc_:
public static void log(int sMsg) UM#.`
{ {NQCe0S+p
System.err.println(sMsg); Mvue>)g~>
} ' tHa5`
} VM:|I~gJ
}JWkV1
o$Ylqb#
/* 9pPLOXr ,
**TestMethod.java [=BMvP5
*/ P;@j
package NetFox; G@`ZDn
)[cuYH>
c{dabzLy
public class TestMethod { _;U%`/T b
=-_hq'il
UX[s5#
public TestMethod() j#2EQ
{ ///xx/weblogic60b2_win.exe u]7wd3(
try{ a??8)=0|}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); A)4XQF
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :s&dn%5N"
SiteFileFetch fileFetch = new SiteFileFetch(bean); UPP"-`t
fileFetch.start(); #qmsZHd}b
} SE43C %hv
catch(Exception e){e.printStackTrace ();} 122s7A
dCS f$5
]jm:VF]4
} }IZw6KiN
kxd*B P
W1M322]>L
public static void main(String[] args) {l5fKVb\C
{ W7b m}JHn
new TestMethod(); $2}#):`
} JB].ht
} L-:@Om!
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