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)); t.wB\Kmt\
} 4AdZN5
for(int i=0;i<nEndPos.length-1;i++) 0>hV?A
{ k(l
nEndPos = nStartPos[i+1]; J6pQ){;6
} tlhYk=yq
nEndPos[nEndPos.length-1] = nFileLength; Y1RiuJtL
} ^q``f%Xt
} L=Cm0q 3v
XBQ]A89G
0}:- t^P
//启动子线程 gC^4K9g
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q/[|/uNw?
for(int i=0;i<nStartPos.length;i++) ^M?O
{ ^8dd
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7hAFK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), g/H:`J
nStartPos,nEndPos,i); y9W6e"
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -I."= c%
fileSplitterFetch.start(); L"|4 v
} y\-f{I
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), AQX~do\A
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Qw>ftle
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", W vh3Y,|3
nEndPos = " + nFileLength); bvHF;Qywg
// fileSplitterFetch[nPos.length-1].start(); 5 :O7cBr
^Mw>'*5^
s;oDwT1
//等待子线程结束 +EI+@hS
//int count = 0; TI '(
//是否结束while循环 9 Yv;Dom
boolean breakWhile = false; WjfUbKg0
Y1e>P
q2Xm~uN`)
while(!bStop) k.Tu#7
{ aD yHIh8
write_nPos(); aXi5~,Ks_
Utility.sleep(500); o$dnp`E
breakWhile = true; 7WZ).,qxY
}bj dK
J:s^F n
for(int i=0;i<nStartPos.length;i++) >uMj}<g#Z?
{ SQ*dC
if(!fileSplitterFetch.bDownOver) _-^bAr`z
{ /?<tjK' "H
breakWhile = false; MUo}Qi0K
break; _T[=7cn
} w!$|IC
} tI651Wm9
if(breakWhile) l2>ka~
break; 4VtI8f!
z#qlu=
dz^l6<a"n
//count++; 4;G:.k!K
//if(count>4) IyTL|W6
// siteStop(); CiE
} A`E7V}~
9uk}r; %9
1~! 4
System.err.println("文件下载结束！"); VCOz?Y*
} 4]c.mDo[T
catch(Exception e){e.printStackTrace ();} hrfu\cI
} WfbG }%&J
sZ`C "1cX
5<o8prtB
//获得文件长度 bZ!*s
public long getFileSize() Uj!3H]d
{ H{*~d+:ol
int nFileLength = -1; 2qEm,x'S
try{ CA2 ,
URL url = new URL(siteInfoBean.getSSiteURL()); 0IHcyb
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ZA4NVt.yN
httpConnection.setRequestProperty("User-Agent","NetFox"); <0my,hAK
!acm@"Ea
gg;&a(
int responseCode=httpConnection.getResponseCode(); O 0Fw!IQk
if(responseCode>=400) u&)+~X
{ rUC@Bf
processErrorCode(responseCode); e1'<;;; L
return -2; //-2 represent access is error v-`RX;8
} o&2(xI2
%T:~N<8)
56i9V9{2
String sHeader; /15e-(Zz/
y8T%g(
u<`CkYT
for(int i=1;;i++) ve|:z
{ 8 VMe#41
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); xA|72!zk0P
//Utility.log(in.readLine()); ><odBM-
sHeader=httpConnection.getHeaderFieldKey(i); V+7x_>!&)
if(sHeader!=null) P;R`22\3
{ =]r<xON%S
if(sHeader.equals("Content-Length")) qaK9E@l
{ 8=;'kEU
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); JGH;&UYP
break; `Q d_Gu,M
} >;Er[Rywr
} KCR6@{@
else I$@0FSl
break; :BLD&mb"Y
} {"<D$*K~
} 7hPiPv
catch(IOException e){e.printStackTrace ();} ;0lHi4 c0
catch(Exception e){e.printStackTrace ();} -3 .Sr|t
'UGkL;
.Y}~2n
Utility.log(nFileLength); Ba$&4?8
M*|,05>
gkDyWZG B
return nFileLength; k&-SB -
} m[~fT(NI
.W_'6Q+
QKW;r
//保存下载信息（文件指针位置） >BU"C+a8g
private void write_nPos() d{?X:*F
{ sem:"
try{ tOx)t$ix
output = new DataOutputStream(new FileOutputStream(tmpFile)); eH.~c3o
output.writeInt(nStartPos.length); _tJp@\rOz=
for(int i=0;i<nStartPos.length;i++) rPf<8oH
{ b}DxD1*nsI
// output.writeLong(nPos); G:'hT=8
output.writeLong(fileSplitterFetch.nStartPos); 6CoDn(+z
output.writeLong(fileSplitterFetch.nEndPos); /"w%?Ea
} 0[(TrIpXl
output.close(); @edx]H1~^
} Z(F`M;1>xI
catch(IOException e){e.printStackTrace ();} QMUmPx&
catch(Exception e){e.printStackTrace ();} !zc?o?~z
} WCc7 MK
d\% |!ix
: b9X?%L~
//读取保存的下载信息（文件指针位置） zo!e<>o
private void read_nPos() T0=8 U; =
{ mQ# 0c_
try{ oC"1{ybyl
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1ztL._Td
int nCount = input.readInt(); -\ {.]KL
nStartPos = new long[nCount]; 3iKBVN
nEndPos = new long[nCount]; #^|"dIZ_M
for(int i=0;i<nStartPos.length;i++) ma__LWKM,
{ ;JQ:S~K9
nStartPos = input.readLong(); Fp3NWvu
nEndPos = input.readLong(); h+,Eu7\88
} PNNY_t +I
input.close(); l_Eeus
} 46p%y
catch(IOException e){e.printStackTrace ();} kkvG=
catch(Exception e){e.printStackTrace ();} re\pE2&B
} J['pBlEb\
y2nwDw(xF
P*9vs%W
private void processErrorCode(int nErrorCode) :=CRsQAn
{ UBj"m<
System.err.println("Error Code : " + nErrorCode); (RhGBgp
} >M`ryM2=D
S5a?KU
3m2hB%SNb
//停止文件下载 -SF*DZ
public void siteStop() ix.I)
{ x^0MEsR
bStop = true; h5+L/8+J^z
for(int i=0;i<nStartPos.length;i++) 5Vq&w`sW
fileSplitterFetch.splitterStop(); -pb>=@Yq
TOH!vQP
+;@p'af!9
} \xtY\q,[
} I=vGS
//负责部分文件的抓取 y9/x:n&]
**FileSplitterFetch.java OE{PP9eh
*/ s,~p}A%0
package NetFox; #.Q8q
A9:dHOmT^U
[pAW':
import java.io.*; reO^_q'
import java.net.*; `XmT)C
q!r4"#Y"@Z
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public class FileSplitterFetch extends Thread { #YEOY#
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String sURL; //File URL ggP#2I\
long nStartPos; //File Snippet Start Position liU/O:Ap
long nEndPos; //File Snippet End Position X3# AYn,
int nThreadID; //Thread's ID i,3[0*ge
boolean bDownOver = false; //Downing is over ` D9sEt_/
boolean bStop = false; //Stop identical 2PaRbh{"
FileAccessI fileAccessI = null; //File Access interface ..Dr?#Cr
6/4?x)l3-
Hea76P5$P+
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException w%Bo7 'o)V
{ r=S6yq}
this.sURL = sURL; c;M&;'#x
this.nStartPos = nStart; FxK2 1
this.nEndPos = nEnd; =o<iBbK#|
nThreadID = id; O)Wc\-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :)PAj
} M@wQ6ow
_7k6hVQ
VK~ OL
public void run() udjahI<{
{ )9PP3"I
while(nStartPos < nEndPos && !bStop) L)mb.U$`c|
{ u`j9m@`
Uiz#QGt
"c'K8,+?
try{ uyfH;9L5$
URL url = new URL(sURL); vz^w%67&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .3Ag6YI0N
httpConnection.setRequestProperty("User-Agent","NetFox"); :SUU)jLq
String sProperty = "bytes="+nStartPos+"-"; F~C9,`#Wf@
httpConnection.setRequestProperty("RANGE",sProperty); vT&xM
Utility.log(sProperty); s/"l ?d
CnvM>]
?)2&LVrf
InputStream input = httpConnection.getInputStream(); 0>aAI3E
//logResponseHead(httpConnection); m:sT)
Kx@Papn|6
-$Ad#Eu]M
byte[] b = new byte[1024]; 9pPohR*#V
int nRead; GQR|t?:t
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) REaU=-m-
{ ^rP` .Z
nStartPos += fileAccessI.write(b,0,nRead); XoO#{7a
//if(nThreadID == 1) Vw P+tM
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8rXQK|A
} TSPFi0PP
Ck;>9>
S.Z2gFE&tu
Utility.log("Thread " + nThreadID + " is over!"); /3>5ex>PN
bDownOver = true; SD=kpf;
//nPos = fileAccessI.write (b,0,nRead); 555*IT3b
} 6(9S'~*'R
catch(Exception e){e.printStackTrace ();} E/Ng
} ~dpU DF
} L]_1z
!}[,ODJ4 d
q!sazVaDp
//打印回应的头信息 IeZgF>
public void logResponseHead(HttpURLConnection con) TS~>9h\;
{ <691pkX
for(int i=1;;i++) /@!%/Kl
{ I<["ko,t@?
String header=con.getHeaderFieldKey(i); ,$xV&w8f\"
if(header!=null) {imz1g;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {okx*]PIc
Utility.log(header+" : "+con.getHeaderField(header)); [ BpZ{Ql
else Ns*&;x9
break; 2yt)"DnFk
} R[l9f8
} x)h|!T=B~
1_aUU,|.
:MIJfr>z
public void splitterStop() YaWZOuxm
{ Q=+*OQV29
bStop = true; LZ?z5U:
} WLB@]JvTBY
7tEkQZMDI
l4:5(1
} DF>LN%a~
\@3B%RW0
XlPi)3m4/S
/* AD** 4E
**FileAccess.java sFvu@Wm'7W
*//文件访问(定位，写) zOEdFU{x
package NetFox; 3/j^Ao\fw
import java.io.*; PqhR^re0.
N3Yf3rK
rKtr&w7X
public class FileAccessI implements Serializable{ D #`o
Bc^%1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 gE_i#=bw
RandomAccessFile oSavedFile; a___SYl 'K
long nPos; 3t*e|Ih&j5
a (mgz&*
^~iFG+g5
public FileAccessI() throws IOException sghQ!ux
{ re$xeq\1P?
this("",0); 'UW(0 PXw
} hI^Hqv
T&ECGF;Y/
C`++r>
public FileAccessI(String sName,long nPos) throws IOException N>+s8L.?
{ vz[-8m:f
oSavedFile = new RandomAccessFile(sName,"rw"); 0# )I:5
this.nPos = nPos; kzK4i!}
oSavedFile.seek(nPos); vq.~8c1
} P_[A
T[z}^"
5Dhpcgq<<
public synchronized int write(byte[] b,int nStart,int nLen) dv_& ei
{ )}G?^rDH(
int n = -1; Gl4(-e'b
try{ y,i ~w |4
oSavedFile.write(b,nStart,nLen); em@bxyMm
n = nLen; ZSBa+3;z
} FRSz3^Aw
catch(IOException e) Zgw;AY.R>
{ #)qn$&.H
e.printStackTrace (); 'R{XqHP
} L,m'/}$
4)cQU.(*k
9(\eL9^
return n; A<1:vV
} 7M|!N_ $
}k`-n32)|
n%SR5+N"
} )*b dG'}
yR`X3.:*]
'V*ixK8R0
/* 6;O fh
**SiteInfoBean.java J$]-)`[G&
*/ @scy v@5)F
package NetFox; sULCYiT|Hn
f>*D@TrU
C\Y%FTS:
public class SiteInfoBean { {.D^2mj|
vxey$Ir
jGeil qPC
private String sSiteURL; //Site's URL _F2R x@Y
private String sFilePath; //Saved File's Path x)wlp{rLf
private String sFileName; //Saved File's Name k3pY3TA@w+
private int nSplitter; //Count of Splited Downloading File 1\[En/6
%![%wI?
V!|:rwG2
public SiteInfoBean() NSsLuM=.
{//nSplitter的缺省值为5 c}QWa"\2n
//default value of nSplitter is 5 RS8tE(
this("","","",5); ?!uj8&yyf
} w_>SxSS7
*_qW;l7
&B3[:nS2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) rt_k }
{ {\SJr:
sSiteURL= sURL; d,hKy2
sFilePath = sPath; )P>}uK;
sFileName = sName; k3 YDnMRA9
this.nSplitter = nSpiltter; (=T%eJ61
(3_m[N\F
#835$vOe
} @`IMR$'
}#b[@3/T
5>S<9A|Q
public String getSSiteURL() mh4<.6>5
{ ,4OH9-Q1
return sSiteURL; %6%QE'D
} M9t`w-@_w
vi4lmkyh^
J%:D%=9 )
public void setSSiteURL(String value) pZ IDGy=~
{ Wv4x^nJ
sSiteURL = value; &4dh$w]q
} iB1+4wa
jQV.U~25Q
qgk-[zW#
public String getSFilePath() =B/Ac0Y
{ M%vZcP
return sFilePath; HRG2sv T4t
} Z ZMz0^V
g]ct6-m
Hy*_4r
public void setSFilePath(String value) -J`VXG:M
{ /Cl=;^)
sFilePath = value; FUD M]:XQ
} ZJod=^T
#C`IfP./
O 8\wH
public String getSFileName() Q&@~<!t
{ [8Yoz1(smA
return sFileName; [%1 87dz:D
} #cF ?a5
,~TV/l<
G|LJOq7QB
public void setSFileName(String value) F.DRGi.i
{ i:@n6GW+iw
sFileName = value; x3QQ`w-
} aOOkC&%
($vaj;
.Z2zv*
public int getNSplitter() jW!x!8=
{ =_@Q+N*]|(
return nSplitter; i+Fk
} pAY[XN
S*D Bzl
1%^d<%,]
public void setNSplitter(int nCount) g(b:^_Nep
{ "(QI7:iM
nSplitter = nCount; 8euh]+
} t#eTn";
} X *fle
(UGmbRf&
)2YZ [~3
/* :8CYTEc
**Utility.java {T=rsPp<@
*/ AgU 7U/yk
package NetFox; ~Bi{k'A9
H"n@=DMLm
pRTdP/(OQ
public class Utility { nWzGb2Y
@9}SHS
)h&*b9[B=
public Utility() WokQ X"
{ }w%W A&"W
*9?T?S|^$F
M .J
} z!0}Kj
L(ni6-
//线程睡眠 ;<~lzfs
public static void sleep(int nSecond) xdV $dDCT
{ SaA9)s
try{ Z^?YTykH
Thread.sleep(nSecond); zm9_[0
} &qP@WFl
catch(Exception e) w*-1*XNA
{ l*0`{R
e.printStackTrace (); OM4q/!)A]
} `tjH#W`
} yS2[V,vS7
rQ!X
//日志 VdfV5"
public static void log(String sMsg) Hc"FW5R
{ 4[$D3,A
System.err.println(sMsg); qt !T%K
} S}T*gUO
x.:k0;%Q
oP0ZJK&;
public static void log(int sMsg) ?xgrr7
{ cYafQyU
System.err.println(sMsg); )b_ GKA `
} ue~?xmZg
} hG3p"_L
n;5;D
/cN. -lEo%
/* iOO1\9{@
**TestMethod.java ,aLdW,<6
*/ 'r2VWavT
package NetFox; _H(:$=$Q
G^ 2a<?Di
\a|bx4M
public class TestMethod { RlH~<|XK
mI[$c"!BD
~1`ZPLVG
public TestMethod() N+[ |"v
{ ///xx/weblogic60b2_win.exe n~wNee
try{ 1Z+\>~8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); " ~X;u8m
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \1p_6U7
SiteFileFetch fileFetch = new SiteFileFetch(bean); ; {P"~(S%
fileFetch.start(); ~{O9dEI
} 9u->.O: p
catch(Exception e){e.printStackTrace ();} OGjeE4
B9-Nb 4
u,rieKYF
} H:DTvv8e{
ezOZHY>|#
8O)!{gB
public static void main(String[] args) 5>e3srKu
{ -'sn0_q/e
new TestMethod(); GG}(*pOr
} ^uy2qO4Yw
} 9b0M'x'W5
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