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)); j"$b%|
} G3?a~n^b
for(int i=0;i<nEndPos.length-1;i++) MgK(gL/&[
{ s)&R W#:X
nEndPos = nStartPos[i+1]; aid)q&AcQ
} {D2d({7
nEndPos[nEndPos.length-1] = nFileLength; A`8}J4
} 4#Nd;gM2
} $}h_EI6hS
Hd@T8 D*A
>5@ 0lYhH
//启动子线程 Y<$"]@w
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; T6?d`i i1
for(int i=0;i<nStartPos.length;i++) `9"jHw`D
{ x?k |i}Q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vR.6^q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1~ZHC[ `
nStartPos,nEndPos,i); V@s/]|rf,
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x:wq"X
fileSplitterFetch.start(); +z/73s0~
} <h>fip3o
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9mtC"M<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /SM#hwFxJ&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 2!& ;ZcT,
nEndPos = " + nFileLength); ;og<eK
// fileSplitterFetch[nPos.length-1].start(); gRd1(S
#S74C*'8
a{YVz\?d}
//等待子线程结束 :QY9pT
//int count = 0; Rn^N+3o'M
//是否结束while循环 u6&Ixi/s'
boolean breakWhile = false; o\YdL2:X
kR|DzB7
nQ*oOxe|X
while(!bStop) j W]c9u
{ )uJ`E8>-
write_nPos(); 97 X60<
Utility.sleep(500); BHBR_7
breakWhile = true; pv.),Iv-68
!LSWg:Ev+
L.&Vi"M <@
for(int i=0;i<nStartPos.length;i++) *wl_8Sis}
{ <^$b1<@
if(!fileSplitterFetch.bDownOver) Z19y5?uR
{ :EAfD(D{)
breakWhile = false; VH*(>^OfF
break; E)SOcM)
} zT40,rk
} obkv ]~
if(breakWhile) l@9:VhU(
break; Eu_0n6J
*J-jr8&
q"vT]=Y}:
//count++; @y%qQe/g
//if(count>4) 5WX2rJ8z
// siteStop(); n m$G4Q
} x?$Y<=vT
SaScP
Qx#)c%v\\
System.err.println("文件下载结束！"); 3Q6#m3AWY
} gC:E38u
catch(Exception e){e.printStackTrace ();} -Euy5Y
} W#/Ol59
hkm3\wg
Zz ?y&T
//获得文件长度 P,], N)
public long getFileSize() *gKr1}M
{ {=Y&q~:8v
int nFileLength = -1; V)@scB|>,
try{ "@Fxfd+Ot
URL url = new URL(siteInfoBean.getSSiteURL()); 8BdeqgU/_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n*|-"'j
httpConnection.setRequestProperty("User-Agent","NetFox"); OuH]Y70(
YRXe j
ot6Pq}
int responseCode=httpConnection.getResponseCode(); vDL/PXNC
if(responseCode>=400) Ku# _
{ ZaV@}=Rd8
processErrorCode(responseCode); =ye}IpC*M
return -2; //-2 represent access is error Tj#XsD?J
} N:zSJW`1
Melc-[
h Nwb.[
String sHeader; vUNE!j
zAIC5fvu
Lr&tpB<
for(int i=1;;i++) 'LI)6;Yc
{ DKH9O
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h)8_sC
//Utility.log(in.readLine()); Sy55w={
sHeader=httpConnection.getHeaderFieldKey(i); bvKi0-
if(sHeader!=null) }2{#=Elh
{ c`Cn9bX
if(sHeader.equals("Content-Length")) Ky|0IKE8Z
{ BcWReyO<M
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~>|U%3}]
break; x(~l[hT
} x@)u:0
} IU}`5+:m
else o\#e7Hqbh
break; #wfR$Cd
} 5=\b+<pE
} .#}R$}e+
catch(IOException e){e.printStackTrace ();} Nt?B(.G
catch(Exception e){e.printStackTrace ();} B'yrXa|P
e$Ej7_.#;
L\5n!(,0
Utility.log(nFileLength); UWp(3FQ
+$C5V,H~
H{If\B%1t
return nFileLength; n@f@-d$m\<
} q.4DwY5 L
KAGq\7
ek<U2C_u#
//保存下载信息（文件指针位置） 3$TpI5A
private void write_nPos() .W\Fa2}%av
{ Pt$7U[N
try{ Sk xaSJ"
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]v#Q\Q8>
output.writeInt(nStartPos.length); Fa8>+
for(int i=0;i<nStartPos.length;i++) /}wGmX! -!
{ rHznXME$wZ
// output.writeLong(nPos); w$_ooQ(_;Q
output.writeLong(fileSplitterFetch.nStartPos); }0 Z3Lrv
output.writeLong(fileSplitterFetch.nEndPos); %rkUy?=vu
} 3JwmLGj}
output.close(); iPao54Z
} '(?@R5a
catch(IOException e){e.printStackTrace ();} zT@vji%Y
catch(Exception e){e.printStackTrace ();} Rh39x-`Z
} SRMy#j-
zK}.Bhj#
9E+^FZe
//读取保存的下载信息（文件指针位置） {"s8X(#_sC
private void read_nPos() XS>4efCJ
{ x9a0J1Nb-h
try{ fYpy5vc-dm
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9,4a?.*4~
int nCount = input.readInt(); HG3jmI+u>
nStartPos = new long[nCount]; 9.<$&mVk7`
nEndPos = new long[nCount]; U`D"L4},.
for(int i=0;i<nStartPos.length;i++) F$.M2*9
{ NWFZ:h@v
nStartPos = input.readLong(); W /IyF){
nEndPos = input.readLong(); +:D0tYk2B
} ]RV6(|U4_
input.close(); 2e+DUZBoC
} 8YCtU9D
catch(IOException e){e.printStackTrace ();} !5ppA
catch(Exception e){e.printStackTrace ();} 'kp:yI7w
} rLp0VKPe
*<J**FhcMu
{R(q7ALR
private void processErrorCode(int nErrorCode) 778a)ZOzb
{ ${e{#
System.err.println("Error Code : " + nErrorCode); a&j H9
} 9n1O@~
VPK)HzPG,
L,n'G%
//停止文件下载 od!TwGX
public void siteStop() By%aTuV$
{ w}+jfO9
bStop = true; ^,,|ED\M{m
for(int i=0;i<nStartPos.length;i++) Yf|+p65g
fileSplitterFetch.splitterStop(); znD0&CS9q
/1Ndir^c
s+,JwV?b
} PE-VxRN)
} <.#i3!
//负责部分文件的抓取 b16\2%Ea1
**FileSplitterFetch.java (|<}q-wO
*/ ONg_3vD{
package NetFox; iWO16=
L -<!,CASW
j&u{a[Y/}
import java.io.*; whr[rWt@>
import java.net.*; y3kXfSe
<$R'y6U:
=56O-l7T*w
public class FileSplitterFetch extends Thread { Iy'a2@
Dhv ^}m@
"cj6i{x,~w
String sURL; //File URL 5V]!xi
long nStartPos; //File Snippet Start Position k,OP*M
long nEndPos; //File Snippet End Position ;5MI8
int nThreadID; //Thread's ID yO.q{|kX
boolean bDownOver = false; //Downing is over OjFB_ N
boolean bStop = false; //Stop identical h:[%' htz
FileAccessI fileAccessI = null; //File Access interface &( aw
M*$#j|
?t46TV'G
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0M-=3T
{ 16Cd0[h?
this.sURL = sURL; @vs+)aRa
this.nStartPos = nStart; dv1Y2[
this.nEndPos = nEnd; k>SPtiAs
nThreadID = id; rvouE:
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8`Ih> Dc
} *:}9(8d
5L!EqB>m;
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public void run() =^3 Z L
{ }xJ ).D
while(nStartPos < nEndPos && !bStop) *sz:c3{_
{ [&eG>zF"
Pg4go10|
M-7^\wXTA
try{ 3:qn\"Hj
URL url = new URL(sURL); K-<<s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fkk&pu
httpConnection.setRequestProperty("User-Agent","NetFox"); DXyRNE<G[C
String sProperty = "bytes="+nStartPos+"-"; AO[/-Uij
httpConnection.setRequestProperty("RANGE",sProperty); x<d2/[(}mT
Utility.log(sProperty); cb82k[L6
qg1tDN`s
_O#R,Y2#
InputStream input = httpConnection.getInputStream(); `?=Y^+*!-
//logResponseHead(httpConnection); iewwL7
grVPu! B;
f9$8$O
byte[] b = new byte[1024]; 5LaF'>1yY
int nRead; ,B2p\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Q{=DLm`
{ ({$>o]<h
nStartPos += fileAccessI.write(b,0,nRead); '"C& dia
//if(nThreadID == 1) me@k~!e"z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .VXadgM
} fD3>g{
aE(DNeG-H
U2G[uDa;
Utility.log("Thread " + nThreadID + " is over!"); YgV"*~
bDownOver = true; }y>/#]X
//nPos = fileAccessI.write (b,0,nRead); ?+_Y!*J2b
} GahIR9_2
catch(Exception e){e.printStackTrace ();} k5gvo
} ROi_k4Fj
} HC!5AJ&+}v
W#9A6ir>
j6GR-WQ]t
//打印回应的头信息 gY {/)"
public void logResponseHead(HttpURLConnection con) ovk^
{ o%E-K=a
for(int i=1;;i++) E3V_qT8
{ 3w&Z:<
String header=con.getHeaderFieldKey(i); L'HO"EZFj
if(header!=null) p'4ZcCW?f
//responseHeaders.put(header,httpConnection.getHeaderField(header)); "Wg5eML0
Utility.log(header+" : "+con.getHeaderField(header)); ]|QA`5=$
else ~Dbu;cqR@
break; :Qu.CvYF
} RveEA/&&
} .R^q$U~v3
ra F+Bt`
NQx>u
public void splitterStop() )1/J5DI @8
{ [{PmU~RMYf
bStop = true; Y;=GM:*H
} !-Uq#Ea0/
,8.zbr
, }B{)
} H,(4a2zx
g$U7bCHG
2,rjy|R`
/* ow9Vj$m
**FileAccess.java m!WDXt
*//文件访问(定位，写) |!cM_&
package NetFox; ]t-B-(D
import java.io.*; 08z?i
e@DVf
D26A%[^O
public class FileAccessI implements Serializable{ /mQ9}E4X
e0g>.P@6
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :@,UPc-+
RandomAccessFile oSavedFile; S~ZRqL7ZO
long nPos; nm`}Z'&)
y^:6D(SR
L{u1_
public FileAccessI() throws IOException O7xBMqMf
{ 84c[Z
this("",0); +pjU4>)
} &Ui&2EW
tVHQ$jJY%
g?9%_&/})A
public FileAccessI(String sName,long nPos) throws IOException J Sms \
{ ^"4u1
oSavedFile = new RandomAccessFile(sName,"rw"); 8Og)(BC
this.nPos = nPos; ^ =RSoR
oSavedFile.seek(nPos); i; 3qMBVY~
} qD>D
P"k,[ZQ
l]mn4cn3
public synchronized int write(byte[] b,int nStart,int nLen) ,CjJO -
{ *Bx'g| u
int n = -1; n4G53+y'
try{ }9>X M
oSavedFile.write(b,nStart,nLen); vQL)I
n = nLen; `*Jw[Bnh8
} zNQ|G1o
catch(IOException e) 6|{uZNz
{ }$1Aw%p^
e.printStackTrace (); Ujss?::`G
} 'W|@d8}h
}S>:!9f
TkV$h(#!f&
return n; XrQS?D`
} >jBnNA@
5A*'@Fr'G
4r>buEU
} cRC)99HP
m7~[f7U
d 3}'J
/* &_y+hV{
**SiteInfoBean.java .j0]hn]
*/ m1lfC
package NetFox; Gq r(.
h\^> s$
"227 U)Q
public class SiteInfoBean { ^,KN@
;j/-ndd&&
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private String sSiteURL; //Site's URL xj!_]XJ^w
private String sFilePath; //Saved File's Path =xX\z\[A
private String sFileName; //Saved File's Name $MG. I[h
private int nSplitter; //Count of Splited Downloading File }qOC*k:
q3E_.{t
c{t[iXDG
public SiteInfoBean() #Rdq^TGMi;
{//nSplitter的缺省值为5 !S',V&Yb
//default value of nSplitter is 5 GcPhT
this("","","",5); 6'6@VB
} <~Tlx:
~f2zMTI|
hOx">yki
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?y{C"w!
{ -zVa[&
sSiteURL= sURL; ZR'q.y[k)
sFilePath = sPath; 9{bzxM
sFileName = sName; /-39od0
this.nSplitter = nSpiltter; 7o+!Gts]
1W5\
e+F5FAMR68
} ,&HZvU&
pstQithS
G?]E6R
public String getSSiteURL() q'?:{k$%
{ gH0B[w ]
return sSiteURL; j]<T\O>t>
} bkl'0 p
[,a O*7N
0n,5"B
public void setSSiteURL(String value) WU1o4&OF
{ m=S[Y^tR
sSiteURL = value; <5(8LMF
} WL}6YSC
~]/X,Cf
38Z"9
public String getSFilePath() ZjEO$ts=@
{ !o4xI?
return sFilePath; bYdC.AE
} ) ZOmv
4W.;p"S2
tTyu,%/m
public void setSFilePath(String value) %i%Xi+{3
{ @WEem(@
sFilePath = value; _'H<zZo
} {7eKv+30
:<&}/r
z[v5hhI)4
public String getSFileName() G-3.-
{ 2,&lGyV#
return sFileName; >W'SG3Hmc
} XU9=@y+|v
h;4g#|,
bOck^1Hky
public void setSFileName(String value) 0dkM72p
{ h0.Fstf]
sFileName = value; I I>2\d|
} {C]M]b*F6(
cfeX(0
rY!uc!
public int getNSplitter() fr#lH3
{ ;7`<.y
return nSplitter; {sm={q
} k)v[/#I
dWqFP
M@'V4oUz
public void setNSplitter(int nCount) Jl]]nOBQ/
{ OaCL'!
nSplitter = nCount; l(]\[}.5
} R^B2J+O
} P/I{q s
=H,cwSE+%
gs8L/veP
/* D`t e|K5
**Utility.java HJJ^pk&
*/ 7lVIN&.=
package NetFox; =` i 7?
+1)C&:
<Y orQ>
public class Utility { 7 YK+TGmU^
7@lXN8_f
Z@[,"{Sn
public Utility() jVA~]a
{ 4iLU "~
EkL\~^
*b)b#p
} )2FO+_K?T
oba*w;
//线程睡眠 \9}5}X_x.
public static void sleep(int nSecond) Un/fP1
{ Z>,X$Y6<
try{ ob00(?;H
Thread.sleep(nSecond); 'QS"4EvdD
} 9#(QS+q~
catch(Exception e) kW!:bh
{ DrEtnt
e.printStackTrace (); =N{eiJ.(p
} x5|v# -F ^
} m4DH90~a8
O2,g]t~C
//日志 w3w*"M
public static void log(String sMsg) j?,*fp8
{ Dy@\!F
System.err.println(sMsg); if}]8
} &JlR70gdHi
`az`?`i7
DXz8C -
public static void log(int sMsg) >slN:dr0:
{ %^l&fM*
System.err.println(sMsg); be/1-=m
} [~<',,tA0|
} Gx!RaZ1
oPy zk7{
@c!67Z
/* O|RO j
**TestMethod.java @L!#i*> 9
*/ WHZng QmY
package NetFox; 'c[LTpn4=
+7/*y}.U
93Gur(j^
public class TestMethod { vEe
0:Y`#0qK
(YJAT
public TestMethod() Zax]i,Bx
{ ///xx/weblogic60b2_win.exe g$"eI/o
try{ 4_%FSW8-
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5SL>q`t.bd
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /mwr1GU
SiteFileFetch fileFetch = new SiteFileFetch(bean); .r|vz6tU?
fileFetch.start(); GLQvAHC
} YaZt+WA
catch(Exception e){e.printStackTrace ();} i>Bi&azx
FFeRE{,
h==GdS4
} C9g~l}=$&
).!14Gjo
ptcLJ]+)
public static void main(String[] args) f76|
{ LEngZ~sV/
new TestMethod(); q3-;}+
} }Q=se[((
} )4)iANH?
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