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)); LVR;&Z>j
} l>3M|js@/
for(int i=0;i<nEndPos.length-1;i++) E%wV
{ n9<roH
nEndPos = nStartPos[i+1]; lKh2LY=j
} VTy,43<
nEndPos[nEndPos.length-1] = nFileLength; _ 6+,R
} ?V&Ld$db
} F]K$u<U
ZYwBw:y}y
%5Q7#xU
//启动子线程 f"5lOzj`C
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &y#\1K
for(int i=0;i<nStartPos.length;i++) >5Q^9 9V
{ (uuEjM$3%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "VT{1(]t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), OCbQB5k3
nStartPos,nEndPos,i); Vze!/ED
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); TnvHO_P,
fileSplitterFetch.start(); kbIY%\QSO
} JEK%yMj
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >\6jb&,%O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); I,],?DQX2)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6i9Q,4~
nEndPos = " + nFileLength); j:rs+1bc
// fileSplitterFetch[nPos.length-1].start(); "W?l R4
x*,q Rew
vxbH^b
//等待子线程结束 }<5\O*kX4
//int count = 0; b:}wR*Adc
//是否结束while循环 /I`cS%U
boolean breakWhile = false; ?YkO+?}+
sx)$=~o
KRnB[$3F1
while(!bStop) E>l#0Zw
{ 2R_opbw
write_nPos(); ^G'yaaLXR
Utility.sleep(500); haEZp6Z
breakWhile = true; ~,1-$#R
CO:m]oj
bBeFL~
for(int i=0;i<nStartPos.length;i++) I&'S2=s
{ K^]?@oHO
if(!fileSplitterFetch.bDownOver) ^-e3=&
{ ~WYE"(
breakWhile = false; 75hFyh;u
break; F?RCaj
} YobC'c\~9
} 0]:*v?
if(breakWhile) ;*>QG6Fh
break; 9:CVN@E
~ X]"P4 u
?vht~5'
//count++; ?j&~vy= T
//if(count>4) 1eE]4Z4Q
// siteStop(); JhMrm%
} 9AVK_
$.r}g\43P
7N}\1Di5
System.err.println("文件下载结束！"); q^jqLT&w
} 6S! lD=
catch(Exception e){e.printStackTrace ();} m5'__<
} 2kp|zX(
:uT fhr
%4r!7X|O<
//获得文件长度 =XRgT1>e
public long getFileSize() .^9/ 0.g8t
{ XDrlJvrPL
int nFileLength = -1; )'K!)?&d
try{ d 40'3]/{
URL url = new URL(siteInfoBean.getSSiteURL()); vZ_DG}n11
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W)$|Hm:H
httpConnection.setRequestProperty("User-Agent","NetFox"); 5x1%oC
cOZajC<G
9|G=KN)P:
int responseCode=httpConnection.getResponseCode(); U47k5s(J
if(responseCode>=400) %T,\xZ
{ %`s9yRk9>E
processErrorCode(responseCode); ,h wf
return -2; //-2 represent access is error pxCGE[@`
} wEo-a< (
)K\k6HC.
6&OonYsP
String sHeader; +NzD/.gq
My6]k?;}(
x%:>Ol
for(int i=1;;i++) !cFE^VM_;
{ 0o"<^] _|
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @WDqP/4
//Utility.log(in.readLine()); vU\w3
sHeader=httpConnection.getHeaderFieldKey(i); AP?{N:+
if(sHeader!=null) F"@'(b
{ 0\_R|i_`>
if(sHeader.equals("Content-Length")) ~qLhZR\g^
{ VtPoc(o4]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); kGBl)0pr`x
break; zOu$H[
} i*cE
} 0|DG\&?
else D)/XP
break; ]uj.uWD
} Tm~#wL +r
} v-r[~
catch(IOException e){e.printStackTrace ();} ("P mB?20
catch(Exception e){e.printStackTrace ();} "'H7F,k'
k>z-Zg
"]\":T
Utility.log(nFileLength); whg4o|p
~RR_[t2Z
EH!EyNNb
return nFileLength; Med"dHo7
} ss*2TE7
*V@MAt
g9lg
//保存下载信息（文件指针位置） H{tOCYyD
private void write_nPos() T=f;n;/>
{ DRmh(T
try{ 7q{v9xKy
output = new DataOutputStream(new FileOutputStream(tmpFile)); @SQ*/sw (c
output.writeInt(nStartPos.length); ~cg+BAfu
for(int i=0;i<nStartPos.length;i++) W*/s4 N
{ _I70qz8
// output.writeLong(nPos); KxTYc
output.writeLong(fileSplitterFetch.nStartPos); _^2[(<Gmv
output.writeLong(fileSplitterFetch.nEndPos); $85o%siS'
} 3xCA\*
output.close(); 9jzLXym
} CyBM4qyH
catch(IOException e){e.printStackTrace ();} 23n8,} H,
catch(Exception e){e.printStackTrace ();} WCfe!P?g
} 9:Z~}yX
[Ey%uh 6*
%Ty {1'o
//读取保存的下载信息（文件指针位置） /jL{JF>I
private void read_nPos() RVKaqJ0e<
{ ^%OH}Z`ly
try{ %Pvb>U(Xs
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !\k#{ 1[!
int nCount = input.readInt(); m{yNnJ3O
nStartPos = new long[nCount]; "y ,(9_#
nEndPos = new long[nCount]; vM3|Ti>a'
for(int i=0;i<nStartPos.length;i++) Ef*.}gcU
{ sFz4^Kn
nStartPos = input.readLong(); N n-6/]d#
nEndPos = input.readLong(); mBgx17K/-_
} Y X{
input.close(); [Oy2&C
} AFhG{G'W
catch(IOException e){e.printStackTrace ();} <n~g+ps
catch(Exception e){e.printStackTrace ();} 2mp>Mn~K^
} E~O>m8hF
7R`ZTfD
9kg>)ty@
private void processErrorCode(int nErrorCode) +5}T!r
{ @/2wmza%2
System.err.println("Error Code : " + nErrorCode); E#V-F-@2
} fD}]Mi:V
<.%8j\j(
j8AR#
//停止文件下载 68br
public void siteStop() {|wTZ
{ 9M~$W-5
bStop = true; \,#4+&4b
for(int i=0;i<nStartPos.length;i++) 7Hlh (k
fileSplitterFetch.splitterStop(); .Fz6+m;Z
*M!YQ<7G^d
|/Q."d
} 3LnyQ
} AA%g^PWpR
//负责部分文件的抓取 S@2Jj>3D?
**FileSplitterFetch.java xcRrI|?eC
*/ Jz8#88cY
package NetFox; tZBE& :l
UHl/AM>!
t:@A)ip
import java.io.*; 8uD%]k=#!
import java.net.*; <^c0bY1
`TR9GWU+B
"uERa(i
public class FileSplitterFetch extends Thread { (>lqp%G~
ej53O/hP
.0;k|&eBD
String sURL; //File URL cZF;f{t
long nStartPos; //File Snippet Start Position v&,VC~RN-J
long nEndPos; //File Snippet End Position 0$h$7'a
int nThreadID; //Thread's ID 6]A\8Ty
boolean bDownOver = false; //Downing is over lfhKZX
boolean bStop = false; //Stop identical ,ui'^8{gK
FileAccessI fileAccessI = null; //File Access interface WG=r? xE
Jj!tRZT
5:3$VWLa <
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException krY.Cc]
{ WjxBNk'f
this.sURL = sURL; 8r|
this.nStartPos = nStart; :H:}t>X6Vo
this.nEndPos = nEnd; (=B7_jrl
nThreadID = id; ^ /eSby
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5*'N Q010
} 6 FxndR;
KFG^vmrn
UdgI<a~`k6
public void run() Uy'ZL(2
{ n/Z =q?_
while(nStartPos < nEndPos && !bStop) 0~5}F^8[L
{ 1,D ^,
aL6 5t\2
%31K*i/]
try{ ebwoMG,B-
URL url = new URL(sURL); hUvH t+d
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %pKs- n`
httpConnection.setRequestProperty("User-Agent","NetFox"); (&x\,19U$
String sProperty = "bytes="+nStartPos+"-"; J3E:r_+
httpConnection.setRequestProperty("RANGE",sProperty); u+FftgA
Utility.log(sProperty); J-?(sjIX
j'b4Sbs-f
-+Ji~;b
InputStream input = httpConnection.getInputStream(); 5.UgJ/
//logResponseHead(httpConnection); GB Un" _J
?Og;W9i
NGGd6V%'-
byte[] b = new byte[1024]; !Bbwl-e`
int nRead; :iiTz$yk
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) bvvx(?!
{ 2;7GgO~
nStartPos += fileAccessI.write(b,0,nRead); S(s~4(o>8
//if(nThreadID == 1) wWswuhq<
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KAEpFobYo
} 9:5NX3"p
UZ0O j5B.
@D{[Hj`<
Utility.log("Thread " + nThreadID + " is over!"); !-Q!/?
bDownOver = true; {D.0_=y~2
//nPos = fileAccessI.write (b,0,nRead); 45JLx?rN_
} +@v} (
catch(Exception e){e.printStackTrace ();} QCnVZ" !(
} Y0'^S<ox
} #Jb$AA!z
:|(B[
+& Qqu`)?F
//打印回应的头信息 @2O\M ,g5
public void logResponseHead(HttpURLConnection con) (Gsg+c
{ K?eo)|4)DB
for(int i=1;;i++) g 0=t9J
{ v65r@)\`
String header=con.getHeaderFieldKey(i); ;:1mv
if(header!=null) OPh@H.)^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $$>,2^qr&L
Utility.log(header+" : "+con.getHeaderField(header)); 5< nK.i,
else 2Vr'AEIQ
break; 2M`Ni&v
} ^ZBkt7
} "FD~XSRL
CtxK{:
j KK48S
public void splitterStop() ^jC0S[csw2
{ x&p=vUuukP
bStop = true; Jrl xa3 [
} >rGlj
y['icGU6
3".W
} +fmZ&9hFNJ
'1*MiFxKq
Dne&YVF9V
/* rbWFq|(_
**FileAccess.java !qq@F%tv
*//文件访问(定位，写) H[oi? {L
package NetFox; ?RyvM_(N6
import java.io.*; U:(t9NX b
/iy/2x28>
]t<%>Z$
public class FileAccessI implements Serializable{ IRY2H#:$
'?4[w]0J<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 O#k+.LU
RandomAccessFile oSavedFile; :oQaN[3>_
long nPos; G_RK3E[FK
{QJ`.6Kt
%J'_c|EQM
public FileAccessI() throws IOException 3e:y?hpeL
{ -z94>}Z=
this("",0); O%{>Zo_<
} ],m-,K
eSf:[^
~yg9ZM
public FileAccessI(String sName,long nPos) throws IOException _^ZII
{ {:cA'6f.b
oSavedFile = new RandomAccessFile(sName,"rw"); 8'62[e|=7[
this.nPos = nPos; Yzz8:n
oSavedFile.seek(nPos); To95WG7G
} P'';F}NwfX
V00zk`PH
*QJ/DC$
public synchronized int write(byte[] b,int nStart,int nLen) )LUl?
{ g;1 UZE;
int n = -1; vF1$$7k
try{ ,$>Z= ~x*
oSavedFile.write(b,nStart,nLen); U/X ^
n = nLen; s,8%;\!C
} !LA#c'
catch(IOException e) VB%xV
{ 0rj*SC_
e.printStackTrace (); %8/$CR
} x(Z@R\C-a
=>U~ligu
7;V5hul
return n; |ipppE=
} }K\_N]#6n
u-$AFSt
+iR;D$w
} aJts
>#Yq&@G
Bf.RYLsh6
/* xYq8\9Qb
**SiteInfoBean.java qYs6PLC
*/ 1zffPC8jl
package NetFox; qn .
SE1 tlP
JP]K\nQx'
public class SiteInfoBean { H+Wd#7l,
.0 K8h:I
\v<}{\.|$
private String sSiteURL; //Site's URL R:E:Y|&#
private String sFilePath; //Saved File's Path LxO'$oKZV
private String sFileName; //Saved File's Name 0J"3RTt
private int nSplitter; //Count of Splited Downloading File xHmc8G$zu
DX|kO
cW2:D$Pe
public SiteInfoBean() ,$Mw/fA
{//nSplitter的缺省值为5 d>}%A ]
//default value of nSplitter is 5 4C$,X!kzF
this("","","",5); _<8y^ymo
} @QEVl
&nss[w$%C
, /pE*Yk
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) bP[/
{ gDrqs>8
sSiteURL= sURL; Lv"83$^S9
sFilePath = sPath; e-WaK0Ep
sFileName = sName; )8_0d)
this.nSplitter = nSpiltter; 7g$t$cZby,
QZY(S*Up
'nul{RE*
} UkC\[$-"\
cjL!$OE6
K{c^.&6D
public String getSSiteURL() 2;3q](d
{ [O3R(`<e5
return sSiteURL; z)0Fk
} 2+'&||h
z"-Urd^O
<5.{+!BM
public void setSSiteURL(String value) ` mi!"pmw
{ m-:k]9I
sSiteURL = value; Oj2[(7mO/
} (8{Z@
(]JJ?aAF
%+.]>''a
public String getSFilePath() OCd[P1Y]
{ SaNx;xgi
return sFilePath; $]vR,E
} {>:2Ff]O:
cIX59y#7
`U1"WcN
public void setSFilePath(String value) 3ySnAAG
{ Au {`oxD
sFilePath = value; zAH+{4lC+
} k $);<= ZI
%ug`dZ/
5H79) n>
public String getSFileName() OygYP
{ ?E`J-ncP
return sFileName; F"q3p4-<>
} 1)%o:Xy o
9}4L8?2
qIk6S6
public void setSFileName(String value) i|<*EXB"
{ 4bO7rhve
sFileName = value; FvkKM+?F
} XDn$=`2
YpWu\oP
6O"0?wG+
public int getNSplitter() &^}w|J?
{ '?d[ ip
return nSplitter; 0-5:"SN'
} m'S-h'a
BH}u\K
N\p3*#M
public void setNSplitter(int nCount) .RT5sj\d
{ 5Hr"}|J<8
nSplitter = nCount; UkdQ#b1
} 5W'T7asOh
} R_^:<F0
:( `Q4D~l
.{Xi&[jw
/* k~?@~xm,R
**Utility.java Awj`6GeJ
*/ f_ ::?
package NetFox; -Ju!2by
xGA%/dy,;
-0W;b"]+A
public class Utility { +n0y/0Au
SZgH0W("L
|h3YL!
public Utility() ur'A;B
{ $}&6p6|
u^`B#b'
]@'YlPU
} ";jhj:Xj
L0|u^J
//线程睡眠 rR7}SEa
public static void sleep(int nSecond) m1(rAr1
{ dkXK0k
try{ T# 8O:
Thread.sleep(nSecond); &BQ`4j~.
} +>s[w{Svy
catch(Exception e) F`3I~(
{ rUj]6j=e
e.printStackTrace (); y:457R2F
} UE(%R1Py
} 9@!`,Co
b[/-lNrc
//日志 'a0$74fz
public static void log(String sMsg) z-()7WY
{ k:c)|2
System.err.println(sMsg); !7_Q_h',
} 5T,`j=\
a.q=
SL*B `P~{
public static void log(int sMsg) #"TTI vd0
{ En[cg
System.err.println(sMsg); *t~(_j
} #t;@x_2yD\
} -qs9a}iL
WT1ch0~2
P[D^*}
/* H3&$:h
**TestMethod.java A$ s4Q0Mf
*/ vmL0H)q
package NetFox; ba ,2.|
@o_-UsUX
R7vO,kZ6Q
public class TestMethod { '(ql7
q),yY]5
JD,/oL.KA
public TestMethod() A9[l5E
{ ///xx/weblogic60b2_win.exe 32dR`qb
try{ 3]V"9+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); <zrGPwk
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Qq>M}
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2jA-y!(e
fileFetch.start(); |E|d"_Ma
} $yG=exh3v
catch(Exception e){e.printStackTrace ();} y_QK _R<f
YX-G>.Pc
*;Sj&O
} b1_HDC(
*_@8v?
_},u[+
public static void main(String[] args) ^hLAMaR
{ `O*+%/(
new TestMethod(); D/{hLp{
} o AvX(
} OTSbhI'v
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