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)); )<Fq}Q86
} nTsKJX%\
for(int i=0;i<nEndPos.length-1;i++) Q,nJz*AJ
{ [Ef6@
nEndPos = nStartPos[i+1]; e5RF6roxO
} Q XSS
nEndPos[nEndPos.length-1] = nFileLength; wE[gp+X~
} {W+IUvn
} 9xi nX-x;n
s&hJ[$i
3rVfBz
//启动子线程 IOA2/WQu
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; @C-03`JWuK
for(int i=0;i<nStartPos.length;i++) M*!WXQlud
{ {V,aCr
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gY'-C
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), N0DzFXp
nStartPos,nEndPos,i); lArKfs/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cY5w,.Q/!
fileSplitterFetch.start(); 2&"qNpPtE
} .k:heN2-x
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M>E~eb/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (C;Q<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >?Duz+W)
nEndPos = " + nFileLength); ]_BH"ng}
// fileSplitterFetch[nPos.length-1].start(); vPz$+&{I
lD^c_b
@Jx1n Q^
//等待子线程结束 Ptz##o'{5
//int count = 0; C}#$wge
//是否结束while循环 \TZSn1isZX
boolean breakWhile = false; +Xp1=2Mq
Ur]/kij
fy]c=:EmD
while(!bStop) ollsB3]]
{ VKkvf"X
write_nPos(); zYrJHn#vB
Utility.sleep(500); 1fvN[
breakWhile = true; O\CnKNk,
8>@JW]
V@g v
for(int i=0;i<nStartPos.length;i++) /IN#1I!K
{ wVqp')e
if(!fileSplitterFetch.bDownOver) $*VZa3B\
{ dB6['z)2
breakWhile = false; O wuc9
break; ~`Rar2%B
} c<,LE@V
} "={*0P
if(breakWhile) ,f{w@Er
break; a2Nxpxho
9/!1J
7O'.KoMw
//count++; 7Q]c=i cg
//if(count>4) z3]W #
// siteStop(); pU9.#O
} F)KR8(
N2k<W?wQ
O!%T<2i3
System.err.println("文件下载结束！"); S.4+tf7+
} q8&l%-d`
catch(Exception e){e.printStackTrace ();} O^3kPVr
} p J_+n:_{
3rB0H
gs;^SRE I
//获得文件长度 m3BL
public long getFileSize() 2mnAL#
{ zPND$3&'
int nFileLength = -1; }^iqhUvT F
try{ nX 9]dz
URL url = new URL(siteInfoBean.getSSiteURL()); =qc+sMo
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |dqHpogh
httpConnection.setRequestProperty("User-Agent","NetFox"); 5e$1KN`
MW6z&+Z
s:7/\h
int responseCode=httpConnection.getResponseCode(); "5Y6.$Cuf!
if(responseCode>=400) 'St6a*
{ &:g:7l]g
processErrorCode(responseCode); *s*Y uY%y
return -2; //-2 represent access is error }a$.ngP
} A $gn{ c
n'v\2(&uYN
\OA{&G.
String sHeader; *9"x0bth
~<f[7dBv
vo`&
for(int i=1;;i++) z,G_&5|f%
{ <M@-|K"Eb
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @]vY[O!&;
//Utility.log(in.readLine()); @2/|rq
sHeader=httpConnection.getHeaderFieldKey(i); IGcq*mR=
if(sHeader!=null) zk FX[-'O
{ /W$i8g
if(sHeader.equals("Content-Length")) vUJ;D
{ M/quswn1
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ##=$$1Ki
break; az6&
} (tX3?[ii
} 6sSwSS
else b/'c h
break; W~'xJ
} L"|Bm{Run
} [|OII!"
catch(IOException e){e.printStackTrace ();} b$7]cE
catch(Exception e){e.printStackTrace ();} w!7ApEH1
>MHlrSH2
PlGif)
Utility.log(nFileLength); Bz/Vzc(
\;)g<TwL
Kd`(^
return nFileLength; e4tIO
} L'e^D|
/RxP:>hVv
}_]AQN$'G
//保存下载信息（文件指针位置） p H y
private void write_nPos() $V(]z`b&
{ 2bNOn%!
try{ v.Ba
output = new DataOutputStream(new FileOutputStream(tmpFile)); LpU}.
output.writeInt(nStartPos.length); ZwS:Te9-
for(int i=0;i<nStartPos.length;i++) CJ\a7=*i
{ 'RMUjJ-!
// output.writeLong(nPos); 'dwT&v]@
output.writeLong(fileSplitterFetch.nStartPos); XMuZ}u[U
output.writeLong(fileSplitterFetch.nEndPos); [Cl0Kw.LD
} XP@dg4Z=z
output.close(); fY!?rZ)$
} {Yj5Mj|#
catch(IOException e){e.printStackTrace ();} h=7q;-@7
catch(Exception e){e.printStackTrace ();} @f-X/q]P
} "CT}34l
=%X."i1A
6h;(b2p{
//读取保存的下载信息（文件指针位置） E5&Z={
private void read_nPos() xol%\$|
{ uQ5h5Cfz
try{ fg^25g'_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *,\"}x*
int nCount = input.readInt(); AHb_BgOU*
nStartPos = new long[nCount]; d05xn7%!{
nEndPos = new long[nCount]; $+*nb4
for(int i=0;i<nStartPos.length;i++) NKO"'
{ +` Md5.w
nStartPos = input.readLong(); ,&hv x
nEndPos = input.readLong(); Qg*\aa94
} $o[-xNn1
input.close(); l_^OdQ9D
} ^[?y 2A:
catch(IOException e){e.printStackTrace ();} +F;2FD$
catch(Exception e){e.printStackTrace ();} =}`d
} UBaXS_c\
b#6S8C+@
t?GH V3V
private void processErrorCode(int nErrorCode) 3B1\-ry1M
{ YN8x|DLi?
System.err.println("Error Code : " + nErrorCode); jrib"Bh3,
} Y Zj-%5
,;g%/6X
rnIjpc F
//停止文件下载 V:n0BlZ,B
public void siteStop() cbJgeif
{ vzIo2,/7
bStop = true; jx}&%p X
for(int i=0;i<nStartPos.length;i++) j6qtR$l|
fileSplitterFetch.splitterStop(); AFAg3/
fs!dI
\*$^}8
} !nBbt?*
} *qpu!z2m||
//负责部分文件的抓取 .(@=L1C<}J
**FileSplitterFetch.java KdEvu?
*/ qezWfR`
package NetFox; ,?GwA@~$k:
'Ea3(OsuXn
,&o9\|ih7]
import java.io.*; z9o]);dZ
import java.net.*; Wmbc `XC
|J&\/8Q
\Id8X`,eD
public class FileSplitterFetch extends Thread { cC*WZ]
Jq_\r'YE
?{J1&;j*
String sURL; //File URL !:+U-mb*
long nStartPos; //File Snippet Start Position /$; Z ~^P
long nEndPos; //File Snippet End Position %xgP*%Sv2
int nThreadID; //Thread's ID uX7L1~s-
boolean bDownOver = false; //Downing is over ZX_QnSNZ?
boolean bStop = false; //Stop identical ]j&m\'-s
FileAccessI fileAccessI = null; //File Access interface zdP?HJ=F
Zo=,!@q(
t#(NfzN
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException eXl?f_9
{ +R~]5Rxd
this.sURL = sURL; IogLkhWX
this.nStartPos = nStart; ( fFrX_K]
this.nEndPos = nEnd; ~A0AB `7
nThreadID = id; "@x(2(Y&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +k=*AQt^8
} UC&$8^
JQ+Mg&&Q
\%r#>8c8
public void run() NZGO8u
{ kHK<~srB
while(nStartPos < nEndPos && !bStop) ,88B@a
{ ,.Gp_BI
L`t786 (M
h),;j`PrC
try{ oypLE=H
URL url = new URL(sURL); B} qRz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dwn|1%D
httpConnection.setRequestProperty("User-Agent","NetFox"); (s'xO~p
String sProperty = "bytes="+nStartPos+"-"; 1^k}GXsWmE
httpConnection.setRequestProperty("RANGE",sProperty); P~(&lu/;P
Utility.log(sProperty); uNf'Zeo
Yte*$cJ=
6UIS4_
InputStream input = httpConnection.getInputStream(); 51}C`j|V3{
//logResponseHead(httpConnection); oX6Cd:c-
yc0 1\o
z{R Mb
byte[] b = new byte[1024]; ]FR#ZvM>x
int nRead; B)k/]vz)*D
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }ll&EB
{ i(A`'V8GY
nStartPos += fileAccessI.write(b,0,nRead); *r>Y]VG;S
//if(nThreadID == 1) S> Fb'rJ3
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?~ybFrc
} &'\-M6GW
nR%w5oe
,,FhE
Utility.log("Thread " + nThreadID + " is over!"); (ht"wY#T<(
bDownOver = true; ''2:ZXX
//nPos = fileAccessI.write (b,0,nRead); DI{Qs[
} m<Gd 6V5
catch(Exception e){e.printStackTrace ();} qPu?rU{2
} aeMj4|{\
} 8hV4l'Pa72
i?>>%juK
<a CzB7x
//打印回应的头信息 9'X"a
public void logResponseHead(HttpURLConnection con) :4:U\k;QwA
{ = CXX.%N
for(int i=1;;i++) __z/X"H
{ `34+~;;Jh
String header=con.getHeaderFieldKey(i); 0>,i] |Y
if(header!=null) p@$92> '
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1\TkI=N3
Utility.log(header+" : "+con.getHeaderField(header)); QIwO _[Q
else BT:b&"AR[
break; Vl7V?`_4
} ^b&hy&ag
} V(G{_>>
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q:_-#u
public void splitterStop() CyS.GdyP
{ d.snD)X
bStop = true; H8c -/
} `=TJw,q
~@^pX*%i
*@ \LS!N
} WAr6Dv,8
-P]onD
CwF=@:*d
/* t-FrF</0
**FileAccess.java _T^@,!&
*//文件访问(定位，写) r^d:Po
package NetFox; 0@!-+}i
import java.io.*; 9@(V!G
\p izVt
H|N,nkhH}
public class FileAccessI implements Serializable{ ]gb?3a}A
[MM`#!K%
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 j&?@:Zg v
RandomAccessFile oSavedFile; y#{> tC
long nPos; H+5N+AKb@
6$+F5T
-[lOf
public FileAccessI() throws IOException C'z}jM`g
{ ADZU?7)
this("",0); 7OZjLD{ID
} XuW>GT/
#c1c%27cmm
[tz}H&
public FileAccessI(String sName,long nPos) throws IOException `oH6'+fT`;
{ 7gbu7"Qc
oSavedFile = new RandomAccessFile(sName,"rw"); jTz~ V&^
this.nPos = nPos; K<w$
oSavedFile.seek(nPos); pj'[ H
} <bOi}
arj?U=zy
4T:@W C
public synchronized int write(byte[] b,int nStart,int nLen) $>PV6
{ f>_' ]eM%
int n = -1; U> 1voc
try{ 6<C|O-
oSavedFile.write(b,nStart,nLen); ]EPFyVt~3
n = nLen; T|Fl$is
} (E?X@d iu
catch(IOException e) jG&gd<^
{ iyf vcKO
e.printStackTrace (); .~dNzonq
} jAb R[QR1%
3rw<#t;v
4XXuj
return n; u IGeSd5B
} T4x%dg
EG[Rda
+(3U_]Lu
} [oh0 )wzB
1US4:6xX_
8!(09gW'>
/* FpM0%
**SiteInfoBean.java `z{sDe;
*/ '9d] B^)F
package NetFox; [GqQ6\
YRm6~c
ij+)U`
public class SiteInfoBean { L1J~D?q
&;]KntxB
%qqX-SF0C
private String sSiteURL; //Site's URL 6<h ==I
private String sFilePath; //Saved File's Path J}'a|a@bk
private String sFileName; //Saved File's Name TcM;6h`
private int nSplitter; //Count of Splited Downloading File V*1hoC#
#XPY\n^k
_gl7Ma
public SiteInfoBean() &3_.k
{//nSplitter的缺省值为5 [uD G;We=
//default value of nSplitter is 5 84}Pu%
this("","","",5); 5:sk&0:@U
} TtKV5
T>2_r6;
\x9.[?;=e
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7uW=fkxT
{ o1zKns?
sSiteURL= sURL; Yg kd1uI.
sFilePath = sPath; \7U'p:h=U
sFileName = sName; zIT)Hs5
this.nSplitter = nSpiltter; \]=''C=J
J70r`
L.tW]43K
} fS#I?!*}
%ot4$eY
N0_@=uE
public String getSSiteURL() #l?E2 U4WL
{ f\U(7)2
return sSiteURL; }@H(z
} "F+m}GJ=a
Q^!x8oUF
[;RO=
public void setSSiteURL(String value) {GP#/5$=
{ Qf#=Y j
sSiteURL = value; xg8$ <Ut
} x>TIQU=\
cWS 0B $$
`+0K~k|DC
public String getSFilePath() J=sj+:GS
{ _ ,~D]JYE
return sFilePath; D(&XmC[\Y
} rctGa ,l
:.bBV]6q
tR`^c8gD
public void setSFilePath(String value) @D@_PA)e(
{ cy @",z
sFilePath = value; %-J}m
} ;:A/WU.^
)N'rYS'9
sRKoM
public String getSFileName() e[l#r>NT
{ (R|Ftjs .
return sFileName; MlH0
} 6O0CF}B*
iwx*mC{|A
15\k/[3 #
public void setSFileName(String value) DICS6VG}
{ 5|_El/G
sFileName = value; 3K{G=WE$
} # ;3v4P
ki=]#]rg
*1`q x+1
public int getNSplitter() F*TkQ\y
{ k!)Pl,nJ
return nSplitter; %s*F~E
} m4~>n(
u#Y#,:{
dk>qTY+j5
public void setNSplitter(int nCount) `*-rz<G
{ mGP&NOR0^y
nSplitter = nCount; >\4"k4d}
} h6~H5X
} 'gv~M_
|kK_B :K
nv'YtmR
/* q)Qg'l^f
**Utility.java *wp>a?sG\
*/ _Y _v&
package NetFox; C2(VYw
fq4[/%6,O
h;DLD8L
public class Utility { &<oJw TC
n=qu?xu
|!hN!j*)
public Utility() + C'<*
{ Lm1 -
ESi'3mbeC
/Xf_b.ZM&
} #fT<]j(
zTS P8Q7
//线程睡眠 hmp!|Q[)
public static void sleep(int nSecond) CX3yIe~u
{ :J;&Z{
try{ \w@V7~vA
Thread.sleep(nSecond); XpIl-o&re
} x=YV*
catch(Exception e) Vqp3'=No
{ \$W\[s4I
e.printStackTrace (); qW 2'?B3<
} /7LAd_P6
} +[Bl@RHe^
$iMbtA5aQ
//日志 8Os: SC@Q
public static void log(String sMsg) wn/Y5
{ vR*p1Kq:
System.err.println(sMsg); aW*8t'm;m'
} {n 4W3
^E]y >Y
12LGWhDp
public static void log(int sMsg) nxhn|v
{ ^?R8>97_?
System.err.println(sMsg); 8fWk C<f}
} \V%l.P4>e
} m<I>NYfE
"1z#6vw5a
lQKq{WLFx.
/* WY$c^av<
**TestMethod.java vocWV/
*/ }s@vN8C
package NetFox; &`I7aP|
#u/5 nm
s`I]>e
public class TestMethod { Btyp=wfN[
t7 +U!
?!a8'jfs
public TestMethod() p(fL' J
{ ///xx/weblogic60b2_win.exe XOT|:
try{ H>Q X?>j
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); b*TQKYT
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); w)Z-, J
SiteFileFetch fileFetch = new SiteFileFetch(bean); kK_9I (7c
fileFetch.start(); =-E%vnU
} jL,P )TC
catch(Exception e){e.printStackTrace ();} sUz,F8G
<%"o-xZq7C
FO{?Z%& ;
} 9}$'q$0R]
M$Ow*!DfP
4,.[B7irR
public static void main(String[] args) c"oJcp
{ e)f!2'LL
new TestMethod(); S<81r2LT
} 1~y\MD*-j
} Dio)orc
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