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)); NYyh|X:m
} gRrL[z
for(int i=0;i<nEndPos.length-1;i++) |^0XYBxQ
{ H]P. x!I
nEndPos = nStartPos[i+1]; J cPtwa;q@
} _7<FOOM%8y
nEndPos[nEndPos.length-1] = nFileLength; J{'>uD.@
} 3?[dE<
} u&1q [0y
~:0sk"t$1
;l4[%xld
//启动子线程 #G.ulX
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3%l*N&gsg:
for(int i=0;i<nStartPos.length;i++) ]@dZ{H|
{ ?b*s. ^
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RdWRWxTn8+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?Fi=P#
nStartPos,nEndPos,i); ]|!OP
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F{Z~ R
fileSplitterFetch.start(); }e!x5g
} N+++4;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ! _f9NK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); YT8vP~
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5}:-h>
nEndPos = " + nFileLength); .|hf\1_J
// fileSplitterFetch[nPos.length-1].start(); fo5iJz"Z
hq%?=2'9?
o%v0h~tn
//等待子线程结束 uH/J]zKR
//int count = 0; Z&#('Z
//是否结束while循环 0M*Z'n +
boolean breakWhile = false; S\4tzz @
B&\IGWG(
FR$:"
while(!bStop) W6f/T3
{ 4S5,w(6N
write_nPos(); ao%NK<Lt
Utility.sleep(500); &wie]
breakWhile = true; E'G4Y-
N8k00*p65
6 2'j!"xv
for(int i=0;i<nStartPos.length;i++) >v:y?A,
{ 5Ec6),+&
if(!fileSplitterFetch.bDownOver) t=|evOz]
{ (gy#js#
breakWhile = false; &{ay=Mj
break; 5XO;N s
} Q7*SE%H
} YX=a#%vrl
if(breakWhile) kv3E4,<9
break; 3_txg>P"
4~y(`\0?4
%oq{L]C(rf
//count++; +Fuqchjq
//if(count>4) M%Ji0v38
// siteStop(); G]D+Sl4<7i
} [f)cL6AeF
yGWxpzmRS
bW$J~ynM
System.err.println("文件下载结束！"); 6,)[+Bl
} Q 7
catch(Exception e){e.printStackTrace ();} ~T9/#-e>BF
} QFw +cy
*vflscgt
_I:~@
//获得文件长度 NYE`Kin-
public long getFileSize() hHN'w73z
{ &Nj3h(Ll
int nFileLength = -1; @HQ`~C#Z'
try{ )#P; x"
URL url = new URL(siteInfoBean.getSSiteURL()); 1>*#%R?W
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9XPo3;
httpConnection.setRequestProperty("User-Agent","NetFox"); u\ #"L
a&tSj35*6
]4~lYuI4
int responseCode=httpConnection.getResponseCode(); K#EvFs`s;
if(responseCode>=400) V@Rrn <l
{ E^QlJ8
processErrorCode(responseCode); #OIcLEn%
return -2; //-2 represent access is error aEM%R<e
} ' qWALu
m5L-67[sB
+g` 'J$
String sHeader; BbW^Wxd3
f%Ns[S~r
_jJPbKz
for(int i=1;;i++) q;QbUO
{ /]=C{)8
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >ZPsjQuf"
//Utility.log(in.readLine()); )Gj8X}DM
sHeader=httpConnection.getHeaderFieldKey(i); i;NUAmx
if(sHeader!=null) |o{:ZmzM
{ /`f^Y>4gD
if(sHeader.equals("Content-Length")) B-.gI4xa
{ AmaT0tzJC
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]e^c=O`$
break; }R1< 0~g
} s>0't
} T,]7ICF#
else R<[qGt|L
break; :A1{d?B
} b?TO=~k,
} %ZNI:Uh
catch(IOException e){e.printStackTrace ();} XM1WfjE\
catch(Exception e){e.printStackTrace ();} Z3{>yYR+
7Bb9t
v5By:z
Utility.log(nFileLength); Av"R[)
"$N#p5
vY%d
return nFileLength; 9{-EJ)
} vWRju*Z&
K%"5ImM
k *Q<3@S
//保存下载信息（文件指针位置） YQ39A_e g
private void write_nPos() zN!ZyI$nqP
{ @\0Eu212
try{ 99}(~B
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?0)&U
output.writeInt(nStartPos.length); F">Qpgt
for(int i=0;i<nStartPos.length;i++) eln&]d;
{ q8s0AN'@t'
// output.writeLong(nPos); OJ/,pLYu
output.writeLong(fileSplitterFetch.nStartPos); Ko;{I?c
output.writeLong(fileSplitterFetch.nEndPos); }D7I3]2>
} b+@JY2dvj
output.close(); 0|$v-`P$
} CPP` qt%f
catch(IOException e){e.printStackTrace ();} nyBJb(5"B
catch(Exception e){e.printStackTrace ();} R(2tlZ
} Cz72?[6
+)j$|x~(A
>iD )eB
//读取保存的下载信息（文件指针位置） _acE:H
private void read_nPos() %;e/7`>Ma
{ )^4\,u\@
try{ T(e!_VY|m
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3T"j)R_=l
int nCount = input.readInt(); 2C/$Ei^t
nStartPos = new long[nCount]; /h*>P:i].
nEndPos = new long[nCount]; P^w#S
for(int i=0;i<nStartPos.length;i++) |_`E1Y}}
{ U7oo$gW%|T
nStartPos = input.readLong(); i|T)p_y(!a
nEndPos = input.readLong(); r.#t63Rb
} f2^r[kPX"
input.close(); wtc!>
} r9 ui|>U"
catch(IOException e){e.printStackTrace ();} v=_6XF
catch(Exception e){e.printStackTrace ();} *Txl+zTY
} !eEHmRgg4
|`lzfe
5Cq{XcXV
private void processErrorCode(int nErrorCode) ix(=3/Dgz
{ HuwU0:*
System.err.println("Error Code : " + nErrorCode); 2_zp:v
} O9EKRt
I9:Cb)hbU]
l~6?kFy9h
//停止文件下载 >p.O0G gg
public void siteStop() uoHNn7W
{ %,D<O,N
bStop = true; &jsVw)Ue
for(int i=0;i<nStartPos.length;i++) 87=^J xy
fileSplitterFetch.splitterStop(); bzX\IrJpOZ
q)Fq i
$: ]o]a
} TiYnc3Bz}J
} 7b<je=G6PA
//负责部分文件的抓取 ai nG6Y<O`
**FileSplitterFetch.java \8<BLmf4U
*/ Hm$=h>rY9[
package NetFox; =,Dqqf
WAn~+=Ax
B>GE9y5
import java.io.*; =0G!f$7^i
import java.net.*; _~*,m#uxJ
N5i+3&
Dh5X/y
public class FileSplitterFetch extends Thread { H63,bNS s
_T2=J+"-Kp
)('%R|$ /
String sURL; //File URL Gm(b/qDDe
long nStartPos; //File Snippet Start Position L ]w/P|
long nEndPos; //File Snippet End Position D3)zk@N
int nThreadID; //Thread's ID );Z1a&K5k
boolean bDownOver = false; //Downing is over 9A,^c;
boolean bStop = false; //Stop identical Gi "941zVl
FileAccessI fileAccessI = null; //File Access interface <L`"!~Q
7.Z@Wr?
B<~ NS)w
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException (;q\}u
{ cG?cUw).E
this.sURL = sURL; n84GZ5O>7
this.nStartPos = nStart; |fSe>uVZ
this.nEndPos = nEnd; U7I qST
nThreadID = id; Kt"BE j
fileAccessI = new FileAccessI(sName,nStartPos);//定位 k'#(1(xj
} ik!..9aB
]p;FZ4-T
xA9:*>+>
public void run() >lBD<;T
{ (HSgEs1d
while(nStartPos < nEndPos && !bStop) g_G6~-.9I
{ e_V O3"
:PtF+{N>
ppFe-wY
try{ tUgEeh6
URL url = new URL(sURL); 2Sh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ds&e|VSH;
httpConnection.setRequestProperty("User-Agent","NetFox"); ]ut5S>,"
String sProperty = "bytes="+nStartPos+"-"; $ZNu+tn Y
httpConnection.setRequestProperty("RANGE",sProperty); $dA-2e10
Utility.log(sProperty); Q",0F{'
8HRmQ
e0J6Ae4V[
InputStream input = httpConnection.getInputStream(); z,VD=Hnz
//logResponseHead(httpConnection); jK' N((Hz
^D<r
|]aE<`D
byte[] b = new byte[1024]; KyzFnVH3)
int nRead; ~_s{0g]B
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) HW7; {QMg
{ zkO<-w
nStartPos += fileAccessI.write(b,0,nRead); ] Puy!Q
//if(nThreadID == 1) bd<m%OM""
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &NSY9'N,
} Fr%d}g
X+~ XJ
b*FC\:\
Utility.log("Thread " + nThreadID + " is over!"); Le*.*\
bDownOver = true; D`xHD#j h
//nPos = fileAccessI.write (b,0,nRead); 59#lU~Kv
} H6&J;yT}
catch(Exception e){e.printStackTrace ();} 5ux`U{`m
} me'd6!O9-
} x3u4v~ "-
cZ<A0
6<'21
//打印回应的头信息 8P"_#M?!
public void logResponseHead(HttpURLConnection con) .58qL-iC
{ 4WE6fJ2X
for(int i=1;;i++) Y;)dct
{ Dc+'<"
String header=con.getHeaderFieldKey(i); ixV0|P8,c
if(header!=null) r YF #^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }=|!:kiE
Utility.log(header+" : "+con.getHeaderField(header)); ~j-cS J3
else {O+Kw<d
break; KL ?@@7
} 8@PX7!9
} TARXx>
Q7g>4GZC
5bA)j!#)|X
public void splitterStop() ki{3IEOr}
{ z.CywME<)t
bStop = true; 5l,ZoB8
} Fh*j#*oe
wQ%mN[
0jzbG]pc:E
} @o-B{EH8
LC})ciWa
W,K%c=
/* (?H0+zws^
**FileAccess.java & u!\<\
*//文件访问(定位，写) nN~~cV
package NetFox; @?[1_g_'P
import java.io.*; !=y]Sv~h
rLU/W<F8
sO5?aB&
public class FileAccessI implements Serializable{ 8&Myva
&bhq`>
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 h1(j2S`:
RandomAccessFile oSavedFile; cS.-7
long nPos; (4@lKKiU%H
5o/&T"]@
XK"-'
public FileAccessI() throws IOException Uh'#izm[l
{ Lgz$]Jbl8
this("",0); 2jbIW*
} /1 RAAa
\V>?Do7
+`sv91c
public FileAccessI(String sName,long nPos) throws IOException gt\MS;jMa
{ St<mDTi
oSavedFile = new RandomAccessFile(sName,"rw"); .@"q$\
this.nPos = nPos; @w>zF/
oSavedFile.seek(nPos); WsFk:h'r
} tV9LD>3
lKkN_ (/j
9z I.pv+]
public synchronized int write(byte[] b,int nStart,int nLen) @VN&t:/l
{ @Eb2k!T
int n = -1; ~Xlrvb}LP
try{ ?go:e#
oSavedFile.write(b,nStart,nLen); c!hwmy;
n = nLen; n9;;x%6.I
} 9=,uq;
catch(IOException e) zyg:nKQW
{ m>}8'N)
e.printStackTrace (); /cK%n4l.y
} IG?'zppjd6
m'-|{c
`funE:>,
return n; j,d*?'X
} X1tXqHJF}
t |W)
-B$~`2-
} /j"sS2$U
^>?CMcN4*
AkU<g
/* + <c^=&7Lq
**SiteInfoBean.java s!+"yK
*/ 4Iq'/r
package NetFox; z5*=MlZ)R.
[~\PQYm'
CU:o*;jP
public class SiteInfoBean { dx,=Rd5'
&ff&Y.q~
y[@\j9Hq
private String sSiteURL; //Site's URL 93IFcmO.H@
private String sFilePath; //Saved File's Path "7d-z<^n
private String sFileName; //Saved File's Name z^nvMTC
private int nSplitter; //Count of Splited Downloading File =N);v\ Q$!
O9(r{Vu7u
`Y40w#?uW
public SiteInfoBean() 0)m8)!gj
{//nSplitter的缺省值为5 Zs2-u^3&
//default value of nSplitter is 5 I =Wc&1g
this("","","",5); %g]vxm5?
} zu2HH<E
Q/I)V2a1i
nH !3(X*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $XBAZ<"hd
{ "Dy'Kd%,%/
sSiteURL= sURL; Z.i{i^/#(
sFilePath = sPath; %b?$@H-Re
sFileName = sName; o$.e^XL
this.nSplitter = nSpiltter; !5}l&7:(MN
|DF9cd^
iv(5&'[p
} "tS'b+SJ-S
ZiFooA
JM.XH7k
public String getSSiteURL() 'rb'7=z5
{ .r+hERcB
return sSiteURL; uqyB5V0gh
} "k$JP
d h^^G^
$!A:5jech
public void setSSiteURL(String value) f]8I64
{ ]J2:194
sSiteURL = value; lo&#(L+2
} W&"|}Pi/
$mA5@O~C5\
IB9%QW"0
public String getSFilePath() nL]^$J$
{ P5QQpY{<I
return sFilePath; ']ood!
} /"qcl7F
V_U'P>_I
M~6@20$oW
public void setSFilePath(String value) O$!*%TL
{ !wLg67X$ -
sFilePath = value; S\NL+V?7h
} eyw'7
VY 1vXM3y
qBk``!|s]
public String getSFileName() oCi ~P}r
{ CPazEe1S
return sFileName; S(eQ{rSs
} Ja^ 5?Ar|
1D([@)^
ZC^C
public void setSFileName(String value) '3l$al:H^
{ 5iFV;W
sFileName = value; VFD%h }
} MN;/*t
cJ}QXuuUv
oholt/gb+0
public int getNSplitter() 1@sM1WMX
{ 0WxCSL$#I
return nSplitter; r@)A k
} QBE@(2G}C
j,%EW+j$
T*q"N?/4
public void setNSplitter(int nCount) !#D=w$@r:
{ v$|mo;6
nSplitter = nCount; \94jrr
} {M~lbU
} V`a+Hi<P\
XbvDi+R2A
17UK1Jx,
/* $.e)
**Utility.java ,qFA\cO*
*/ ~0tdfK0c
package NetFox; yDd[e]zS`
8LM#WIm?
T.?k>Ak
public class Utility { ( 76{2
- HOnB=
nf%4sIQ*x
public Utility() 7$T8&Mh
{ &&RA4
!r&Bn6*
\%_ZV9cKF
} r)l`
6517Km 4-
//线程睡眠 j64 4V|z
public static void sleep(int nSecond) $@[)nvV\
{ MR9/Y:Nm
try{ x6yW:tUG5
Thread.sleep(nSecond); ,r+"7$
} XdIah<F2
catch(Exception e) JAb$M{t
{ mA{#]Yvf1
e.printStackTrace (); =&NOHT>
} a>Re^GT+z
} WVL#s?=g
J 3?Dj
//日志 hH4o;0rqJ
public static void log(String sMsg) Sni=gZK
{ 6&!l'[hU
System.err.println(sMsg); (.^8^uc7X
} 6Dzs?P
j=3-Qk`"/|
_-a|VTM
public static void log(int sMsg) QPg2Y<2
{ E[S':Q
System.err.println(sMsg); @W9H9PWv&
} O3_B<Em
} co]Gmg6p
Va9q`XbyO
V<0$xV1b|=
/* d(l|hmj4j9
**TestMethod.java ofwQ:0@
*/ qC j*>D
package NetFox; *wUdC
@l,{x|00
q+/l"&j.
public class TestMethod { BjD&>gO)
EzP#Mnz^
bXl8v
public TestMethod() lP0k:
{ ///xx/weblogic60b2_win.exe Ow3a0cF[9
try{ ,C!n}+27
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); xii$e
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); BvJ=iB<E
SiteFileFetch fileFetch = new SiteFileFetch(bean); ONWO`XD
fileFetch.start(); =J.EH|
} 8t``NZ[
catch(Exception e){e.printStackTrace ();} %|?1B$s0
!GNXt4D
1o#vhk/"+
} zz3 r<?#5
[:pl-_.C
DcU C,
public static void main(String[] args) Q&wYc{TUbm
{ ^@q#$/z
new TestMethod(); QN #)F
} :0dfB&7
} !fZLQc
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