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)); BkC(9[Ei
} 5H',Bm4-
for(int i=0;i<nEndPos.length-1;i++) n XQg(!
{ i?a]v 5
nEndPos = nStartPos[i+1]; )ejvT-
} n_w,Ew,>5
nEndPos[nEndPos.length-1] = nFileLength; W6*(Y
} WpvH} l r}
} X!"y>J
Dg]i};
KYeA=
//启动子线程 A7sej
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; EdU3k'z$
for(int i=0;i<nStartPos.length;i++) 6Qo6T][
{ iffU}ce
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), E O}(MXS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^oP]@r"qy
nStartPos,nEndPos,i); @emZwN"m
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); uD5i5,q1Hs
fileSplitterFetch.start(); ,<[os
} #VrT)po+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |, :(3Ml
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Dp'/uCW)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1k hwwoo
nEndPos = " + nFileLength); _\1(7?0D
// fileSplitterFetch[nPos.length-1].start(); +6>Pp[%
1E-$f
|W::\yu6
//等待子线程结束 2L\h+)
//int count = 0; {vU '>pp
//是否结束while循环 "5e]-u'
boolean breakWhile = false; 1ri#hm0x\
&iSQ2a!l8b
Mu:H'$"'H
while(!bStop) C=Zuy^
{ >LNl8X:Cz*
write_nPos(); FKzqJwT
Utility.sleep(500); }\irr9,
breakWhile = true; 5<S1,u5
U%#=d@?
(z.Vwl5
for(int i=0;i<nStartPos.length;i++) G9gvOEI/
{ \2LCpN
if(!fileSplitterFetch.bDownOver) 1DBzD%@Oz
{ !K@yB)9
breakWhile = false; ^8\pJg_0
break; G(4k#jB
} $M><K
} y}3V3uqK
if(breakWhile) y_nh~&
break; 7X.1QSuE
ar{e<&Bny
>Te{a*`"m:
//count++; 7eO8cPy
//if(count>4) I?:V EN:
// siteStop(); |;].~7^
} Lf,gS*Tg?
68d@By
^a]i&o[c
System.err.println("文件下载结束！"); {wm `
} ZzE&?
catch(Exception e){e.printStackTrace ();} oNdO@i%.q4
} H4pjtVBr
9#agI|d~
Hnaq+ _]
//获得文件长度 1|%$ie
public long getFileSize() 7,jqA"9
{ 7Jqp2\
int nFileLength = -1; $~j]/U
try{ [IYs4Y5
URL url = new URL(siteInfoBean.getSSiteURL()); HsXFglQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !F%dE!
httpConnection.setRequestProperty("User-Agent","NetFox"); gi`ZFq@
+I')>6
U_J|{*4S.!
int responseCode=httpConnection.getResponseCode(); OO@$jXZB
if(responseCode>=400) VP"L_Um
{ 7j]@3D9[:p
processErrorCode(responseCode); {k)MC)%
return -2; //-2 represent access is error cEN^H
} Z]6D0b
yWs/~5[F
}`eeItI+
String sHeader; 1|`9Hp6
57#:GN$EL
X$xqu\t7
for(int i=1;;i++) "47nc1T+n
{ 8=?I/9Xh
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -8TLnl~[
//Utility.log(in.readLine()); Di L@NU!$q
sHeader=httpConnection.getHeaderFieldKey(i); Z<wg`
if(sHeader!=null) n b{8zo
{ #(A>yW702
if(sHeader.equals("Content-Length")) 4ASc`w*0
{ t EN%mK
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Gh< r_O~L3
break; ;<*VwXJR
} aH~il!K
} -}>Q0d)
else Z2ZS5a
break; O[m+5+
} +Y\#'KrA
} e]5QqM7
catch(IOException e){e.printStackTrace ();} e5AiIVlv
catch(Exception e){e.printStackTrace ();} I7}[%(~Sf/
]02V,'x
HH]LvK
Utility.log(nFileLength); }X`K3sk2/z
.$r(":A#)
S5XFYQ
return nFileLength; * 5j iC
} [[)HPHSQ
2qEy"DKu
V^Nc0r
//保存下载信息（文件指针位置） "B\qp"N
private void write_nPos() lKa}Bcd
{ v<c8qg
try{ } o=g)
output = new DataOutputStream(new FileOutputStream(tmpFile)); @hCGV'4
output.writeInt(nStartPos.length); M^bujGD
for(int i=0;i<nStartPos.length;i++) +XQS -=
{ <?I~ +
// output.writeLong(nPos); 1M+mH#?
output.writeLong(fileSplitterFetch.nStartPos); ^,rbA>/L
output.writeLong(fileSplitterFetch.nEndPos); L-Hl.UV
} |+[bKqI5
output.close(); h qxe
} m=#2u4H4
catch(IOException e){e.printStackTrace ();} )UxF lp;\
catch(Exception e){e.printStackTrace ();} oZIoY*7IrQ
} 9SU;c l
.qHgQ_%
!]"T`^5,Y
//读取保存的下载信息（文件指针位置） cLXMq"?C
private void read_nPos() eQNYfWR
{ }6o` in>M
try{ Xl}>mbB
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Mbi)mybM
int nCount = input.readInt(); lT%o6qgT
nStartPos = new long[nCount]; OW6i2>Or
nEndPos = new long[nCount]; bclA+!1
for(int i=0;i<nStartPos.length;i++) $V@IRBm
{ DQE.;0ld
nStartPos = input.readLong(); e}Db-7B_~
nEndPos = input.readLong(); +4@EJRC
} a|OX4
input.close(); P ^D\znvc
} No h*1u*
catch(IOException e){e.printStackTrace ();} yDHH05Yl
catch(Exception e){e.printStackTrace ();} p( z.[
} yYW>)
w 5,-+&;
U/TF,JUI
private void processErrorCode(int nErrorCode) UGAP$_j ]P
{ d#A.A<p*
System.err.println("Error Code : " + nErrorCode); m. XLpD
} O8M;q!)y
eE7+fMP{
j]jwQRe
//停止文件下载 TT>;!nb
public void siteStop() j{nL33T%
{ eO*FoN
bStop = true; cm-!6'`
for(int i=0;i<nStartPos.length;i++) "zYlddh
fileSplitterFetch.splitterStop(); %SIbpk%
WJl&Vyl2FL
ZX'/[wAN)
} &t`l,]PQ=6
} lh .p`^v
//负责部分文件的抓取 2r\f!m'
**FileSplitterFetch.java %kyvtt
*/ uN'e~X6
package NetFox; Ut0oh
V+DN<F-
$My%7S/3
import java.io.*; X62GEqff
import java.net.*; g }5lGz4
mhVSZhx|
rBT#Cyl
public class FileSplitterFetch extends Thread { }+,;wj~
0>>tdd7
O$KLQ'0"n
String sURL; //File URL t}]=5)9<
long nStartPos; //File Snippet Start Position '(~+ \
long nEndPos; //File Snippet End Position )88z=5.
int nThreadID; //Thread's ID )]?sCNb
boolean bDownOver = false; //Downing is over :6%wVy5
boolean bStop = false; //Stop identical 6 fL=2a
FileAccessI fileAccessI = null; //File Access interface )%gigQZ+
H71LJfH
Koo%mr
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `cCsJm$V"
{ N<9CV!_
this.sURL = sURL; R9^Vk*`gFU
this.nStartPos = nStart; RYy_Ppn96f
this.nEndPos = nEnd; e'p'{]r<w
nThreadID = id; l7nc8K
fileAccessI = new FileAccessI(sName,nStartPos);//定位 'tklz*
} `gx_+m^
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r 1nl!
public void run() ;3 O0O
{ 1o V\QK&
while(nStartPos < nEndPos && !bStop) g>cp;co9g
{ =:uK$>[
%;~Vc{Xxt/
n~@;[=o?5
try{ P|l62!m<
URL url = new URL(sURL); I^emH+!MW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j!F5gP-l
httpConnection.setRequestProperty("User-Agent","NetFox"); [}|x@ v9
String sProperty = "bytes="+nStartPos+"-"; !Qy%sY
httpConnection.setRequestProperty("RANGE",sProperty); nd}[X[ay
Utility.log(sProperty); w9G (^jS6
=# <!s!
JgEPzHgx
InputStream input = httpConnection.getInputStream(); ">@]{e*
//logResponseHead(httpConnection); `O5wM\Z
0NL~2Qf_4
C|*U)#3:F
byte[] b = new byte[1024]; W9+H/T7!
int nRead; I r]#u]Ap
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 'pa[z5{k+
{ ;p)RMRMg
nStartPos += fileAccessI.write(b,0,nRead); 3rBSwgRl
//if(nThreadID == 1) gY|f[M|
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &@<Z7))
} GHWi,' mr
~=67#&(R
*eK\W00
Utility.log("Thread " + nThreadID + " is over!"); "wy|gnQJ
bDownOver = true; yS'W ss
//nPos = fileAccessI.write (b,0,nRead); K&3,J7&&
} ^ ~'&K e
catch(Exception e){e.printStackTrace ();} 8iA[w-Pv
} }OL?k/w
} f#f<Ii
UuPXo66F]
L7VDZCV
//打印回应的头信息 $KHw=<:)/
public void logResponseHead(HttpURLConnection con) 7@oM?r7td
{ >"5f B
for(int i=1;;i++) W8,4LxH
{ Ve)P/Zz}^
String header=con.getHeaderFieldKey(i); GJS3O;2*
if(header!=null) D~P3~^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); hg4d]R,
Utility.log(header+" : "+con.getHeaderField(header)); tpPP5C{
else `1 A,sXfa
break; >}?jOB
} A{NKHn>%`
} 4&N#d;ErC
4}.PQ{
/Z^"[Ke
public void splitterStop() [J{\Ke0<e1
{ Y&wtF8
bStop = true; =>3wI'I
} #0kVhx7%
Is&0h|
8z1#Q#5
} WVZ](D8Gc]
8L1vtYz
Ec'Hlsgh&T
/* X(_xOU)V
**FileAccess.java O2{~Q{p
*//文件访问(定位，写) !B|Aq- n,
package NetFox; v'RpsCov
import java.io.*; w2X0.2)P2
/{Mo'.=Z
27J!oin$
public class FileAccessI implements Serializable{ Cfs2tN
vG'6?%38
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 )+7|_7 !x
RandomAccessFile oSavedFile; nwS @r
long nPos; u1 Z;n
c~``)N
f4 k
public FileAccessI() throws IOException e'I/}J
{ (/gv U80
this("",0); cV$an
} a_Sp}s<J
FP=up#zl
,ArHS
public FileAccessI(String sName,long nPos) throws IOException qPQ6`rD\
{ Nwwn #+
oSavedFile = new RandomAccessFile(sName,"rw"); )fy-]Ky *
this.nPos = nPos; r{>`"
oSavedFile.seek(nPos); `uP:UQ9S
} 2x5^kN7
(n{x"rLy/
z`}z7e'>
public synchronized int write(byte[] b,int nStart,int nLen) 6.Jvqn
{ &zR\Rmpt
int n = -1; 3#A4A0
try{ \+)aYP2Hu
oSavedFile.write(b,nStart,nLen); "_^vQ1M]Z
n = nLen; Bo,>blspw
} whi#\>i
catch(IOException e) *O|_)G
{ %<)!]8}P*
e.printStackTrace (); 4bs<j
} \E(^<Af
Y1Q240
k=W~ot&
return n; 8$F"!dc _
} I1pnF61U
w!dgIS$
d88Dyzz
} +0ALO%G;G"
_`I}"`2H
v!`:{)2C
/* &HQ_e$1
**SiteInfoBean.java ;~-ZN?8
*/ TMsc5E
package NetFox; Ct][B{
jj&mRF0gCb
2U|"]tpM&
public class SiteInfoBean { 3qW](
Z=9<esx
tzShds
private String sSiteURL; //Site's URL :5sjF:@
private String sFilePath; //Saved File's Path g#k@R'7E
private String sFileName; //Saved File's Name \ 5.nr*5
private int nSplitter; //Count of Splited Downloading File x2,;ar\D
h2-v.Tjf
}_Ci3|G>%D
public SiteInfoBean() 7qSnP30}
{//nSplitter的缺省值为5 Sse%~:FL
//default value of nSplitter is 5 7@&mGUALO
this("","","",5); 9^u}~e #(
} J8-K
7W'&v+\
Ze!/b|`xI
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) O _C<h
{ ,\?s=D{
sSiteURL= sURL; 6gabnW3
sFilePath = sPath; v2IcDz`}7
sFileName = sName; CcTdLq
this.nSplitter = nSpiltter; :7M%/#Fy
+zwS[P@
:_,a%hb+8
} 9Af nMD
~470LgpO1
**$kWbS
public String getSSiteURL() @d5$OpL$%
{ J&Db-
return sSiteURL; RBz"1hRo`
} /Xq|SO
IgjPy5k
1M.#7;#B3
public void setSSiteURL(String value) 25f[s.pv8
{ L@'2}7N1%
sSiteURL = value; MDQ:6Ri
} #zv&h`gY
h3bQ<?m
7H*,HZc@=
public String getSFilePath() Q;N)$Xx
{ :t9sAD
return sFilePath; ?V}ub>J/=
} -X_\3J
G1-r$7\
IL:[0q
public void setSFilePath(String value) Oq$-*N
{ RH{+8?0
sFilePath = value; }3, 4B-8!
} S\]9mHJI
.820~b0
tU$n3Bg
public String getSFileName() *<:6A&'D9
{ /0cm7[a?
return sFileName; <)pPq+
} cNT !}8h^
|)v}\-\#
mU(v9Jpf7
public void setSFileName(String value) rizjH+
{ MQDLC7Y.p5
sFileName = value; 7O8 @T-f+2
} $}IG+,L
$vK,Gugcx
_X
public int getNSplitter() .Tm.M7
{ rg;4INs#
return nSplitter; 8bQXC+bK
} [m4M#Lg\0
w2!:>8o:
e$teh` p3
public void setNSplitter(int nCount) DE7y\oO]
{ AOkG.u-k
nSplitter = nCount; U'msHF
} T{2)d]Y
} !Pz#czo
FGPqF;
ps?su`
/* $IS!GS&:
**Utility.java C~ A`h=A<
*/ ?hAO-*);
package NetFox; YcV^Fqi!
qO38vY){
BQ<\[H;
public class Utility { |'&$VzA
5Ok3y|cEx
x4PzP
public Utility() ]%I\FefT
{ #?+[|RS|
FZ}^)u}o
K2e68GU
} 4DDBf j
E|>-7k")
//线程睡眠 NV-l9
public static void sleep(int nSecond) WO{7/h</
{ mR|5$1[b
try{ t9MCT$U
Thread.sleep(nSecond); wfe4b
} w N`Njm9!
catch(Exception e) FfxD=\
{ &SPY'GQ!
e.printStackTrace (); pH.&C 5kA
} C-)d@LWI
} PH&Qw2(Sx
JWaWOk(t=?
//日志 '^C *%"I]
public static void log(String sMsg) Qe7=6<
{ mR1b.$
System.err.println(sMsg); )A%* l9\nG
} IiRQ-,t1
y$bY 8L
$T#fCx/
public static void log(int sMsg) 5-ED\-
{ {tl{j1d|
System.err.println(sMsg); _yJz:pa
} ?<BI)[B
} %'i_iF8.
_&\'Va$
QcX\z\'vg
/* s3m\
**TestMethod.java |c8\alw
*/ +c!HXX
package NetFox; rM,f7hm[S*
^&C/,,U
p-_9I7?
public class TestMethod { E3Y0@r
Tn/Zs|
Cse`MP
public TestMethod() ?>{u@tYL
{ ///xx/weblogic60b2_win.exe ]LZ#[xnM7
try{ R) :Xs.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *k;bkd4x
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /*>}y$
SiteFileFetch fileFetch = new SiteFileFetch(bean); YmFg#eS
fileFetch.start(); t:V._@
} j0X^,ot@m
catch(Exception e){e.printStackTrace ();} jIr\.i
kr~n5WiAZ
N?-ZvE\C
} 1kpw*$P0
y\uBVa<B
K> 4w
public static void main(String[] args) +ctU7 rVy
{ &L5 )v\z
new TestMethod(); XEbVsw
} 0,)2\`99#k
} VD@$y^!H
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