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)); @Z,qu2~|!
} ju r1!rg%
for(int i=0;i<nEndPos.length-1;i++) V3%Krn1'
{ kU>#1He
nEndPos = nStartPos[i+1]; k\%,xf; x
} &7lk2Q\
nEndPos[nEndPos.length-1] = nFileLength; {MA@A5
} =cknE=
} m_~y
!__D}k,
@gY'YA8m
//启动子线程 EqYz,%I%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0.3^
for(int i=0;i<nStartPos.length;i++) a?l_-Fi
{ !HbqbS22
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 37,L**Dgs
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), C!`>cUhE{
nStartPos,nEndPos,i); c;nx59w]q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EGr|BLl
fileSplitterFetch.start(); 9k*^\@\\x
} =nw,*q +
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), YcEtgpz@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }isCvb
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8x`Kl(
nEndPos = " + nFileLength); ,d3Q+9/
// fileSplitterFetch[nPos.length-1].start(); \;'_|bu3.
;}$Z 80
VoWA tNU
//等待子线程结束 m]Hb+Y=;h
//int count = 0; o8iig5bp
//是否结束while循环 oPp!*$V
boolean breakWhile = false; Qs~d_;
Bi$ 0{V Z8
HIQ]"Hl
while(!bStop) Q>##hG:m
{ 5+J64_
write_nPos(); t*5z1T?
Utility.sleep(500); @G7w(>_T3
breakWhile = true; QZ6[*_Z6
Ax :3}
6yy|V~5
for(int i=0;i<nStartPos.length;i++) <=#lRZW[z
{ )R8%wk?2
if(!fileSplitterFetch.bDownOver) A!Knp=Gw
{ TB;3`
breakWhile = false; qr7 X-[&
break; >Iu]T{QNO
} (R9QBZP5
} m+;B!46
if(breakWhile) (rau8
break; <W=~UUsn
K'a#Mg
'Wo?%n
//count++; ocb%&m;i
//if(count>4) !hwzKm=%N
// siteStop(); ^aGZJiyJ
} l{M;PaJ`}
)Ix-5084
@>qx:jx(-S
System.err.println("文件下载结束！"); /5L'9e
} 8<E!rn-
catch(Exception e){e.printStackTrace ();} -lJx%9>
} y|&.v<
BnKP7e
]}UeuF\
//获得文件长度 u=_bM2;~Z
public long getFileSize() yEMX`
{ !D.= 'V
int nFileLength = -1; i}v}K'`
try{ $.suu^>^w
URL url = new URL(siteInfoBean.getSSiteURL()); )nf=eU4|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [ t>}SE
httpConnection.setRequestProperty("User-Agent","NetFox"); aYv'H
UE}8Rkt
Jdk3) \
int responseCode=httpConnection.getResponseCode(); Zj%B7s1A
if(responseCode>=400) l044c,AW(
{ BLl%D
processErrorCode(responseCode); _QC?:mv6-
return -2; //-2 represent access is error 7/5NaUmPTt
} U.zRIhA]
_mIa8K;
Uxj<x`<1x
String sHeader; %J/fg<W1
"z{_hp{T^
^g}gT-l%
for(int i=1;;i++) :,xyVb+
{ =UI,+P:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }a #b$]Y
//Utility.log(in.readLine()); .!7Fe)(x
sHeader=httpConnection.getHeaderFieldKey(i); $M}k%Z
if(sHeader!=null) Ak%no3:9
{ b@{%qh,C
if(sHeader.equals("Content-Length")) 2|T|K?R^
{ *_2O*{V
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); GY0XWUlC
break; oP43NN~
} X\c1q4oB[
} PsF- 9&_
else @1J51< x
break; z$I[kR%I{
} yi AG'[
} Zh@4_Z9n!
catch(IOException e){e.printStackTrace ();} ]noP
catch(Exception e){e.printStackTrace ();} Et@=Ic^E
rA1zyZlz
O&rD4#
Utility.log(nFileLength); {|7OmslC@
0~@L%~
" kE:T.,
return nFileLength; Tv*1q.MB
} &2P:A
k@cZ"jYA
P0`>{!r6@
//保存下载信息（文件指针位置） QXIbFv
private void write_nPos() )DklOEO
{ pR@GvweA
try{ )$lSG}WD
output = new DataOutputStream(new FileOutputStream(tmpFile)); @Le ^-v4
output.writeInt(nStartPos.length); n!CP_
for(int i=0;i<nStartPos.length;i++) :e0R7sj
{ G]m[S-
// output.writeLong(nPos); *1ID`o
output.writeLong(fileSplitterFetch.nStartPos); Ul7pxzj
output.writeLong(fileSplitterFetch.nEndPos); @> +^<
} pZ@W6}
output.close(); /`j K
} eK=m02
catch(IOException e){e.printStackTrace ();} W=;(t
catch(Exception e){e.printStackTrace ();} YN5OuKMUd'
} R5'Z4.~
v4,syd*3|V
=@ L5
//读取保存的下载信息（文件指针位置） 'EH
private void read_nPos() Gg3?2h"d
{ ~'Qpf 8)
try{ a\[fC=]r:
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); mNBpb}
int nCount = input.readInt(); x jP" 'yU
nStartPos = new long[nCount]; +lDGr/
nEndPos = new long[nCount]; NBbY## w0
for(int i=0;i<nStartPos.length;i++) @tjZvRtZ
{ %xbz&'W,
nStartPos = input.readLong(); &ls!IN
nEndPos = input.readLong(); =?I1V#.
} )l[7;ZIw$
input.close(); Vbqm]2o&
} 1=o(sIeA
catch(IOException e){e.printStackTrace ();} 3' :[i2[
catch(Exception e){e.printStackTrace ();} Bgo"JNM
} 79c9+
( F"& A?
v&CO#vK5.
private void processErrorCode(int nErrorCode) f-f\}G&G
{ EDa08+Y
System.err.println("Error Code : " + nErrorCode); U7f&N
} NkjQyMF
No92Y^~/
Vp{RX8?.
//停止文件下载 {7M4SC@p|
public void siteStop() )*$
{ ~A:;?A'.
bStop = true; b$`4Nn|
for(int i=0;i<nStartPos.length;i++) ]B[/sqf
fileSplitterFetch.splitterStop(); Q'Jpsmwu
%f3Nml
E{k%d39>
} L[[H&#\
} )l!&i?h%
//负责部分文件的抓取 IpaJ<~ p
**FileSplitterFetch.java !i"9f_
*/ dC;d>j,
package NetFox; >`,#%MH#
b09#+CH?
K~hlwjrt
import java.io.*; H@&"M%
import java.net.*; I`n1M+=%
yn ?U7`V
EBn:[2
public class FileSplitterFetch extends Thread { .n|3A3:
@l6dJ
ZsK'</7
String sURL; //File URL V\7u
long nStartPos; //File Snippet Start Position )mo|.L0
long nEndPos; //File Snippet End Position ?k7/`gU
int nThreadID; //Thread's ID d7-F&!sQ
boolean bDownOver = false; //Downing is over GL0':LsZ
boolean bStop = false; //Stop identical |sZ9/G7
FileAccessI fileAccessI = null; //File Access interface O9 Au =
TXk"[>,:H
ea[a)Z7#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException U-^S<H
{ m5Laq'~0_
this.sURL = sURL; BxN#Nk~
this.nStartPos = nStart; s].Cx4VQ
this.nEndPos = nEnd; wYxFjXm
nThreadID = id; Z(`K6`KM
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @Oc}\Rg
} _q!ck0_
V@s/]|rf,
k}a!lI:
public void run() 0BwQ!B.
{ Zo6a_`)d
while(nStartPos < nEndPos && !bStop) E6IL,Iq9
{ g8@i_
_"e( ^yiK
' xq5tRg>
try{ Wv'B[;[)
URL url = new URL(sURL); Z"8cGN'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #2t\>7]
httpConnection.setRequestProperty("User-Agent","NetFox"); :QY9pT
String sProperty = "bytes="+nStartPos+"-"; nLLHggNAV
httpConnection.setRequestProperty("RANGE",sProperty); u6&Ixi/s'
Utility.log(sProperty); +( 7vmC.
[~H`9Ab=
HDG"a&$
InputStream input = httpConnection.getInputStream(); Jx[e{o)o
//logResponseHead(httpConnection); |vE#unA
n7<-lQRaxZ
F,$$N>
byte[] b = new byte[1024]; \A"a>e
int nRead; 24k}~"We
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) T{2//$T?
{ ep1Ajz.l
nStartPos += fileAccessI.write(b,0,nRead); S^_yiV S
//if(nThreadID == 1) 3JO:n6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]o[HH_`s@
} E)SOcM)
H zK=UcD
dKG<"
Utility.log("Thread " + nThreadID + " is over!"); F#9KMu<<cI
bDownOver = true; 3Jit2W4
//nPos = fileAccessI.write (b,0,nRead); vYun^(_-
} -2XIF}.Hu
catch(Exception e){e.printStackTrace ();} qoq<dCt3
} PltPIu)F
} 667tL(
$9b6,Y_-
NWcF9z%@
//打印回应的头信息 l)eaIOyk
public void logResponseHead(HttpURLConnection con) 3Q6#m3AWY
{ unB "dE
for(int i=1;;i++) ^E8Hv
{ F.w#AV
String header=con.getHeaderFieldKey(i); @uWD>(D
if(header!=null) `OK }q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); p`ZGV97
Utility.log(header+" : "+con.getHeaderField(header)); A~t7I{`
else \%*y+I0>
break; /qY(uPJ
} ~~ w4854
} t38T0Ao
Z ISd0hV
]5L3[A4Vu
public void splitterStop() ;#Nci%<J\
{ ~nlY8B(
bStop = true; &wvv5Vd
} AY]nc#zz
"R]K!GUU
`hhG^O_
} YLr2j 7
#.aLx$"a
3Pq)RD|hn
/* r-uIFhV^
**FileAccess.java g==^ioS}*
*//文件访问(定位，写) ZaV@}=Rd8
package NetFox; w|ei*L
import java.io.*; [!$>:_Vq/
c}cboe2
h Nwb.[
public class FileAccessI implements Serializable{ Ved:w^ ,
F!<x;h(
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %;gWl1&5
RandomAccessFile oSavedFile; :zoX Xo
long nPos; -"H9W:
wm4e:&
.YlM'E*X
public FileAccessI() throws IOException K ajyQ"j
{ S]a$w5ZP
this("",0); &!Vp'l\9
} YWdvL3Bgk,
_X/`4 G
z@j&vW
public FileAccessI(String sName,long nPos) throws IOException :4TcCWG
{ N"{o3QmA
oSavedFile = new RandomAccessFile(sName,"rw"); V-|}.kOH2
this.nPos = nPos; '`"&RuB
oSavedFile.seek(nPos); F'!}$oT"
} 03y<'n
.?TVBbc%5
VP&lWPA}\$
public synchronized int write(byte[] b,int nStart,int nLen) ShP V!$0
{ `.XU|J*z,
int n = -1; Ab)7hCUW
try{ h:wD &Fh8
oSavedFile.write(b,nStart,nLen); [%y D,8
n = nLen; )*B.y|b#
} r+crE %-
catch(IOException e) #wfR$Cd
{ C09@2M'
e.printStackTrace (); 5=\b+<pE
} R!ij CF\
|V5H(2/nk
aDESO5
return n; O!jCQ{ T
} :n4x}%
@nK08Kj-
xOH@V4z:
} ^EZoP:x(oE
;8UHPDnst
jw)t"S/E
/* >?tpGEZ\
**SiteInfoBean.java inPGWG K]
*/ D]REZuHOI
package NetFox; MtljI6
o/#e y
j~0hAKHG
public class SiteInfoBean { z#b6 aP
.'M]cN~
a>6p])Wh
private String sSiteURL; //Site's URL \uH;ng|m
private String sFilePath; //Saved File's Path Rh|&{Tf
private String sFileName; //Saved File's Name e"Z~%,^A
private int nSplitter; //Count of Splited Downloading File T^ -RP
`B~%TEvMh
e BPMT
public SiteInfoBean() "A7tb39*
{//nSplitter的缺省值为5 A'T! og|5
//default value of nSplitter is 5 <\u%ZB
this("","","",5); P_}$|zj7
} ]v#Q\Q8>
8in8_/x
LdL< 5Q[
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {.AFg/Z
{ i*3'O:Gq
sSiteURL= sURL; xYbF76B
sFilePath = sPath; G|V ^C_:
sFileName = sName; wp$=lU{B
this.nSplitter = nSpiltter; =6'A8d
LS;kq',
+-ue={'
} TAP/gN'
Rh39x-`Z
aX!J0&3
public String getSSiteURL() Ty>`rn
{ Wjp<(aY[
return sSiteURL; {az8*MR=X
} ~dv C$
x~ I cSt
?AR6+`0
public void setSSiteURL(String value) 1'h?qv^(
{ `eA0Z:`g!
sSiteURL = value; ) E5ax~
} Xa36O5$4]9
j&F&wRD%r
umc!KOkL
public String getSFilePath() Bi]%bl>%
{ iC 2:P~
return sFilePath; g\2Y605DM
} GerZA#
LGK}oL'
F$.M2*9
public void setSFilePath(String value) I3$v-OiL
{ 7l?-2I'c
sFilePath = value; `*!.B
} nRvV+F0#
+:D0tYk2B
3N?uY2
public String getSFileName() #+XKfumLk
{ f"/NY6
return sFileName; w$1.h'2
} 8YCtU9D
7:]I@Gc'
U]_1yX
public void setSFileName(String value) 'kp:yI7w
{ |>m@]s7Z
sFileName = value; ?=6zgb"9-
} ezFyd'P
:[Fwc
)V3G~p=0
public int getNSplitter() kIQMIL0+
{ Xf:-K(%e
return nSplitter; q0Fy$e]u
} WKP=[o^
iidK}<o
=*t)@bn
public void setNSplitter(int nCount) gq/q]Fm\
{ =5+:<e,&
nSplitter = nCount; M}HGFN
} xHHG| u
} U4%P0}q/
?'^xO:
7&2xUcsz)
/* Dzb@H$BQ7
**Utility.java S);bcowf_
*/ >QCVsX>~
package NetFox; ^,,|ED\M{m
&6h,'U
}6`#u:OZ
public class Utility { IU&n!5d$)|
lBl`R|Gt
eR?`o!@y
public Utility() +hi!=^b]
{ hCM+=]z"
J-b Z`)[Q
%G>*Pez%
} $33wK
wTqgH@rGtR
//线程睡眠 x]w%?BlS
public static void sleep(int nSecond) G$WMW@fy
{ ?z p$Wz;k
try{ zoA]7pG-
Thread.sleep(nSecond); 1Z|q0-Dw0
} h ~v8Q_6
catch(Exception e) DdPU\ ZWR
{ Lk4gjs,V
e.printStackTrace (); ~#Vrf0w/
} ;=aj)lemCr
} _A1r6
1#6c sZW5
//日志 bvi Y.G3
public static void log(String sMsg) A(ql}cr
{ @}qMI
System.err.println(sMsg); rMUn ~
} wm_xH_{F
Dhv ^}m@
s@V4ny9x
public static void log(int sMsg) ~Cm_=[
{ `|+!H.3
System.err.println(sMsg); uL`_Sdjw
} k,OP*M
} V& _
&i$p5
=[`B -?
/* s +"?j
**TestMethod.java OjFB_ N
*/ ch!/k
package NetFox; "`s{fy~mV
e+Vn@-L;
/{|JQ'gqX
public class TestMethod { ZuH@qq\
6C7|e00v
<>%2HRn<u
public TestMethod() R0HzNk
{ ///xx/weblogic60b2_win.exe )T&ZiHIJ3
try{ gd#+N]C_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); f@rR2xZoQ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }Ox5,S}ra
SiteFileFetch fileFetch = new SiteFileFetch(bean); k>SPtiAs
fileFetch.start(); N"L@
} 9bwG3jn4?
catch(Exception e){e.printStackTrace ();} a'r8J~:jy
#?u#=]
P-U9FKrt
} Xw)W6H|
C;>!SRCp
N3"O#C
public static void main(String[] args) Vq4g#PcG
{ 3qggdi
new TestMethod(); %m)vQ\Vtx
} '(fQtQ%
} #\1)Tu%-
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