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)); )HS|pS:
} wGd8q xa
for(int i=0;i<nEndPos.length-1;i++) ({Fus@/
{ "vH@b_>9|
nEndPos = nStartPos[i+1]; }CaL:kY8
} + }(
nEndPos[nEndPos.length-1] = nFileLength; z|}Anc[\
} eL^,-3JA(]
} x*i5g`jx
;W?e@ Lgxk
2{"Wa|o`
//启动子线程 h(d<':|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; zdyS"H}
for(int i=0;i<nStartPos.length;i++) 6h}f^eJ:K,
{ ^qiTO`lg
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), LB? evewu
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), T'\lntN
nStartPos,nEndPos,i); {4CkF\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); eN>=x40
fileSplitterFetch.start(); >~TLgq*
} XIJ>\ RF
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -:pLlN-f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); itX<!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Mz40([{
nEndPos = " + nFileLength); D!J ("~[3
// fileSplitterFetch[nPos.length-1].start(); [rU8%
?.|qRzWL
vrGRZa
//等待子线程结束 @s2z/h0H
//int count = 0; y M , hF
//是否结束while循环 |w6:mtaS
boolean breakWhile = false; azPFKg+
@]WN|K
M<"&$qZ$R
while(!bStop) D?qA aq&4
{ dy,,x
write_nPos(); T*J]e|aF
Utility.sleep(500); $>OWGueq64
breakWhile = true; Wxb/|?,
hX$k8 o0
GpN tvo~
for(int i=0;i<nStartPos.length;i++) }UHuFff,
{ 76} N/C
if(!fileSplitterFetch.bDownOver) 0mH>fs 4
{ oO$a4|&,
breakWhile = false; #`);UAf
break; m$*dPje
} nW{). P
} h<6@&yzp
if(breakWhile) ?t'O\n)M
break; CO0Nq/@
:v Pzw!
F_zs"ex/
//count++; TaG'?
//if(count>4) +MGEO+
// siteStop(); +aEE(u6%E@
} vxZvK0b620
'RTz*CSZ
ZR6KE_
System.err.println("文件下载结束！"); &0K H00l
} ,;O+2TX
catch(Exception e){e.printStackTrace ();} 4punJg~1
} ;wp)E nF
>7@F4a
,X+mXtg.
//获得文件长度 j*q]-$2E
public long getFileSize() p/cVQ
{ !R[o6V5T
int nFileLength = -1; 6@ET3v
try{ v#(wc+[
URL url = new URL(siteInfoBean.getSSiteURL()); N#6&t8;kTC
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2y,NT|jp
httpConnection.setRequestProperty("User-Agent","NetFox"); qdL;Ii<Y0
1;4TA}'H
&( b\jyf
int responseCode=httpConnection.getResponseCode(); 8D;>]>
if(responseCode>=400) d; oaG (e
{ 1 BAnf9
processErrorCode(responseCode); Tr(w~et
return -2; //-2 represent access is error ;I:jd")
} z./u;/:
g.s~Ph-G
o D*h@yL
String sHeader; km}%7|R?
J5mMx)t@
Nf}G "!
for(int i=1;;i++) ]gQgNn?
{ T,!?+#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,-vbR&
//Utility.log(in.readLine()); RoJ{ ou@cs
sHeader=httpConnection.getHeaderFieldKey(i); &`Z>zT}
if(sHeader!=null) w6qx
{ rKg5?.
if(sHeader.equals("Content-Length")) <Ktx*(D
{ R3jhq3F\Y
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); wx>BNlT@?
break; 5WP)na6"
} \6T&gX
} H8mmmt6g
else C^2Tql
break; \.POb5]p0
} /U`"Xx
} $eCxpb..
catch(IOException e){e.printStackTrace ();} {Ymn_
catch(Exception e){e.printStackTrace ();} 2VrF~+
A]WU*GL2H
Zyu4!
Utility.log(nFileLength); Eii)zo8Xd
KWLI7fTgj$
7Fh%jRHZ`
return nFileLength; G9 ;X=c
} \{\*h/m
MIsjTKE
q#xoM1
//保存下载信息（文件指针位置） GASDkVoij
private void write_nPos() $GSn#} yz
{ fx_7X15
try{ VEkv JX.
output = new DataOutputStream(new FileOutputStream(tmpFile)); quTM|>=_R
output.writeInt(nStartPos.length); & VJ+X|Z
for(int i=0;i<nStartPos.length;i++) [W,Ej
{ i ?%;s5<
// output.writeLong(nPos); d!D#:l3;
output.writeLong(fileSplitterFetch.nStartPos); >KNiMW^V
output.writeLong(fileSplitterFetch.nEndPos); ]t=m
} LS}u6\(
output.close(); 5hr$tkkL
} MXh0a@*]
catch(IOException e){e.printStackTrace ();} K63OjR>H
catch(Exception e){e.printStackTrace ();} &u&/t?
} c/jU+,_g
"iMuA
[o<Rgq4
//读取保存的下载信息（文件指针位置） dzjp,c@
private void read_nPos() \'xF\V
{ /vYuwaWG=
try{ l:-$ulAx
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3,8<5)ds*
int nCount = input.readInt(); ]]Sz|6P
nStartPos = new long[nCount]; %?Yf!)owh
nEndPos = new long[nCount]; w<!F& kQB
for(int i=0;i<nStartPos.length;i++) V8@VR`!'
{ 4QARrG%
nStartPos = input.readLong(); e4fh<0gX
nEndPos = input.readLong(); 2-s ,PQno^
} 66(|3DX
input.close(); i+ ]3J/J
} *39Y1+=)$$
catch(IOException e){e.printStackTrace ();} 3+%a
catch(Exception e){e.printStackTrace ();} S1p4.qJ
} [_Fj2nb*
0Dv r:]R
dY5 m) ?
private void processErrorCode(int nErrorCode) ]0p] u d&
{ 7hQXGY,q
System.err.println("Error Code : " + nErrorCode); InBnU`(r
} v6uR[18
mEeD[dMN
3k(A&]~v
//停止文件下载 3q:U0&F
public void siteStop() Q'5]E{1<'n
{ O`j1~o<{
bStop = true; Lp.dF)C\
for(int i=0;i<nStartPos.length;i++) "Rr)1x7
fileSplitterFetch.splitterStop(); w<#/ngI2
!w2J*E\
#Z#rOh
} C jISU$O
} $9YAq/#Q
//负责部分文件的抓取 NX%"_W/W
**FileSplitterFetch.java $ @g\wz
*/ He vZ}.
package NetFox; a> qB k})
[U'I3x,
v7gs $'Q
import java.io.*; o9\J vJk
import java.net.*; ?*cr|G$r[
v+Mi"ZAd
hGh91c;4
public class FileSplitterFetch extends Thread { l7 Pn5c
2T 3tKX
pse$S=
String sURL; //File URL 0Lb:N]5m8
long nStartPos; //File Snippet Start Position opsjei@
long nEndPos; //File Snippet End Position xl2;DFiYt
int nThreadID; //Thread's ID %])U(
boolean bDownOver = false; //Downing is over w_qX~d/
boolean bStop = false; //Stop identical V1di#i:
FileAccessI fileAccessI = null; //File Access interface o-i9 :AHs
.3>`yL
*ThP->&:(
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4FQB%3>*
{ *Tc lcu
this.sURL = sURL; e_=TkG1E6
this.nStartPos = nStart; StLFq6BO
this.nEndPos = nEnd; O{^8dwg
nThreadID = id; ~H`m"4zQ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 i&mcM_g32
} USd7gOq(
MTXh-9DA
^E~F,]dV=
public void run() rf?%- X(V
{ T,@s.v
while(nStartPos < nEndPos && !bStop) *I]/ [d
{ +2xgMN6B@
9Xl[AVs:M
R*0]*\C z
try{ 7<GC{/^T
URL url = new URL(sURL); *!oV?N[eA'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HpP82X xj
httpConnection.setRequestProperty("User-Agent","NetFox"); ;P *`v
String sProperty = "bytes="+nStartPos+"-"; (yrN-M4~t
httpConnection.setRequestProperty("RANGE",sProperty); 1A%0y)]
Utility.log(sProperty); lT^/8Z<g
-.xiq0
Mc,3j~i
InputStream input = httpConnection.getInputStream(); ?_ 476A
//logResponseHead(httpConnection); Ef @
r)S:-wP
0:I[;Qt
byte[] b = new byte[1024]; sGFvSW
int nRead; H^ 'As;R
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) n)|{tb^
{ V82HO{ D
nStartPos += fileAccessI.write(b,0,nRead); S5o,\wT
//if(nThreadID == 1) eWWqK9B.-
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ] M`%@ps
} ylm #Xa
bT7+$^NHf
e&nE
Utility.log("Thread " + nThreadID + " is over!"); f+!k:}K
bDownOver = true; )Fgu'
//nPos = fileAccessI.write (b,0,nRead); y0f:N U
} ]A%]W^G
catch(Exception e){e.printStackTrace ();} fn#qcZv?
} ) >te|@}o
} -w"$[XP
ui RO,B}z
\&_pI2X
//打印回应的头信息 po\(O8#5U
public void logResponseHead(HttpURLConnection con) 2cEvsvw>
{ RDfvD|}VN
for(int i=1;;i++) )x+P9|
{ j*\oK@
String header=con.getHeaderFieldKey(i); 40%fOu,u`
if(header!=null) [*C%u_h
//responseHeaders.put(header,httpConnection.getHeaderField(header)); WD55(
Utility.log(header+" : "+con.getHeaderField(header)); /:tzSKq}
else fUMjLA|*I<
break; iGPrWe@.
} OxQ5P;O
} &V|kv"Wwj
.Hnhd/ c
d.|*sZ&3p
public void splitterStop() nW)?cQ I
{ dGgltY
bStop = true; GKc?
} 7KesfH?
u*f`\vs
~R&rQJJeJ
} qj9[mBkP"
U&i#cF
Z`_x|cU?J
/* R_D&"&
**FileAccess.java C$p012D1
*//文件访问(定位，写) $DXO7;#
package NetFox; 5tyA{&Ao
import java.io.*; $K.DLqDt
ZC]|s[
inY_cn?
public class FileAccessI implements Serializable{ &gJ1*"$9
B(WmJ6e
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;>uB$8<_7
RandomAccessFile oSavedFile; ",l6-<s
long nPos; !Q WNHL
7t+d+sQ-l
mPU}]1*p
public FileAccessI() throws IOException Zs(BViTb|
{ IsmZEVuC
this("",0); hraR:l D
} eR4ib-nS
:zX^H9'E<(
A!,c@Kv 3
public FileAccessI(String sName,long nPos) throws IOException zMRa<G7
{ @0]w!q
oSavedFile = new RandomAccessFile(sName,"rw"); 0C;Js\>3]
this.nPos = nPos; 8 :WN@
oSavedFile.seek(nPos); h/oun2C
} Fv7]1EO.
[n2zdiiBd
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public synchronized int write(byte[] b,int nStart,int nLen) fF(AvMsO
{ (/2rj[F&
int n = -1; t{>#)5Pqv
try{ \61H(,
oSavedFile.write(b,nStart,nLen); )!kt9lK
n = nLen; tA^+RO4
} T$`m!mQ4
catch(IOException e) o{>4PZ}=g
{ X1d{7H8A2
e.printStackTrace (); 5kGQf
} w[F})u]E
8nng^
=/}Rnl+c
return n; !uit
} JNY?]|=
tmOy"mq67
*xJ]e.
} `v@Z|rv,
X&HYWH'@,
-. o,bg
/* Rz&`L8Bz
**SiteInfoBean.java Zr1"'+-
*/ (u^8=#
package NetFox; r&Nh>6<&/
YO-B|f
e,{k!BXU#'
public class SiteInfoBean { ysZ(*K n(?
q_6lD~~q^
sZ~03QvkT
private String sSiteURL; //Site's URL |||m5(`S
private String sFilePath; //Saved File's Path L*dGo,oN
private String sFileName; //Saved File's Name a_bZT4
private int nSplitter; //Count of Splited Downloading File 7TEpjSuF
@`)>-k
gm pY[
public SiteInfoBean() `*[\b9>
{//nSplitter的缺省值为5 Y#I8gzv
//default value of nSplitter is 5 yZ{N$ch5b
this("","","",5); O:8 u^TP
} S!#5
hxj\
b+q'xnA=>
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) M*bsA/Z
{ vs$h&o>|
sSiteURL= sURL; Qy"%%keV'T
sFilePath = sPath; :-#7j} R&
sFileName = sName; GApvRR+Z
this.nSplitter = nSpiltter; %TRJ
Q|P M6ta
W!T[ ^+
} kssRwe%>;
VRgckh m
ViyG%Sm
public String getSSiteURL() x0>N{ADXQ
{ /s%-c!o^
return sSiteURL; y`8U0TE3R
} WV'u}-v^
7[='m{{=C
:R +BC2x
public void setSSiteURL(String value) </ "Wh4>C
{ 'v^shGI%Ht
sSiteURL = value; x^c,cV+*
} }"nm3\Df
k&:q|[N
ZvQZD=,F
public String getSFilePath() uH?4d!G
{ 5#x[rr{^*
return sFilePath; KztQT9kY
} `KLr!<i()
-hfkF+=U'
%scIZCrI~
public void setSFilePath(String value) A@?-"=h}
{ -6WSYpHV
sFilePath = value; i;/;zG^=_
} UroC8Tm
=bP<cC=3b
Im-qGB0C
public String getSFileName() K:qc "Q=C
{ b@=H$"
return sFileName; Vv5T(~
} kI04<!
%Jd!x{a`>A
~ArRD-_t
public void setSFileName(String value) ^~TE$i<
{ R>~I8k9mM
sFileName = value; ~.J*_0~Ze
} vfj{j= G
8"NPj0
{/N8[?zML
public int getNSplitter() ~*\ *8U@7
{ @*L-lx
return nSplitter; eJn_gKWb
} K?e16;
[~cz|C#
K0o${%'@7
public void setNSplitter(int nCount) wpC.!T
{ C8qSoO4Z
nSplitter = nCount; MQcIH2
} uTz>I'f
} {*g{9`
{,6J*v"o
P_mP ^L
/* `-cw[@uD
**Utility.java x[)]u8^A
*/ 9An\uH)mL
package NetFox; U6wy^!_X9
]Lg~I#/#
H/Ql
public class Utility { Y%y
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2'OY,Ooe
public Utility() @qW$un:
{ 7I]?:%8h
1 |)CQ
l O*
} tQxxm=>
$_eJ@L#
//线程睡眠 S=`$w
public static void sleep(int nSecond) GcA|JS=>
{ wL]#]DiE
try{ ob9od5Rf
Thread.sleep(nSecond); ,afO\oe>MG
} @ZJ}lED3
catch(Exception e) |=~mRqG
{ lfd-!(tXD
e.printStackTrace (); JV4fL~
} #h9Gl@|
} t;PG
8'qlg|{!~
//日志 j"pyK@v2B
public static void log(String sMsg) 5! +{JTXa
{ n)D
System.err.println(sMsg); 3QVUWhJ
} +O8zVWr
u#y)+A2&!
T*C F5S
public static void log(int sMsg) Z!fbc#L6
{ =|empv#
System.err.println(sMsg); #)48dW!n
} *wd=&Z^19
} L*|P'
}.WO=IZ
Uugq.'>
/* R^$EnrY(<
**TestMethod.java =b1 y*?
*/ X&rsWk
package NetFox; |yp^T
)Spa F)N8
D^p)`*
public class TestMethod { *>Bew
PQYJnx}
WD[jEWMV7D
public TestMethod() luac
{ ///xx/weblogic60b2_win.exe |f1^&97=+
try{ 2>9..c
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); r~oUln<[
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6CGk*s
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3fZoF`<a
fileFetch.start(); S5Pn6'w
} y@2"[fo3~
catch(Exception e){e.printStackTrace ();} %1{O
+;pw^QB
q@VIFmqY!
} E[zq<&P@
saQo]6#
&t_TLV 8T
public static void main(String[] args) e}7!A
{ =;)=,+V~q
new TestMethod(); Buq(L6P9r
} EKN<KnU%
} K&gE4;>
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