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)); }.pqV X{d
} m[%':^vSr
for(int i=0;i<nEndPos.length-1;i++) lQiw8qD
{ xkRS?Q g
nEndPos = nStartPos[i+1]; KLW>O_+
} =''WA:,=h
nEndPos[nEndPos.length-1] = nFileLength; Wx8:GBM$2
} S?6-I,]h
} J[05T1
g\?v 5
LEOri=?RF
//启动子线程 ^eyVEN
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; i=*H|)
for(int i=0;i<nStartPos.length;i++) 4JU2x
{ _!VtM#G[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), YXZP-=fB>i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), zy%0;%
nStartPos,nEndPos,i); cWG%>.`5r
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oc]:Ty
fileSplitterFetch.start(); O$;#GpR
} Rnoz[1y?0
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), by0K:*C
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); S~ Z<-@S
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", uY(8KW
nEndPos = " + nFileLength); m?4hEwQxf
// fileSplitterFetch[nPos.length-1].start(); .>#O'Z&q9
J}[[tl
a]7g\rg)
//等待子线程结束 QuG"]$
//int count = 0; DQ3L=
//是否结束while循环 ZgG~xl\My
boolean breakWhile = false; zwU[!i)
u8.Tu7~
+p63J
while(!bStop) [U",yN]d
{ _k26(rdI@-
write_nPos(); 1<1+nGO
Utility.sleep(500); {J izCUo_'
breakWhile = true; Ha|}Oj
1KrJS(.
M_Ag*?2I
for(int i=0;i<nStartPos.length;i++) yyljyE
{ GC7WRA
if(!fileSplitterFetch.bDownOver) M;Pry3J
{ HV)aVkr/&
breakWhile = false; ,dTmI{@O
break; H7.l)'
} O^=+"O]
} Li}5aK
if(breakWhile) k9OGnCW\
break; wEM=Tr/h
~WTkX(\
#"KC29!Yj
//count++; Sx QA*}N
//if(count>4) ObEz0Rj
// siteStop(); -$o0P'Vx
} n<j+KD#a
pXl[I;
C{pOGc@
System.err.println("文件下载结束！"); QK+,63@D\=
} x1#>"z7
catch(Exception e){e.printStackTrace ();} "lw|EpQk`
} qjhV/fsfb
h#O9TB
PBb&.<
//获得文件长度 lTqlQ<`V
public long getFileSize() G2kU_
{ 5[SwF&zZ
int nFileLength = -1; <C&|8@A0
try{ vuPNru" 2
URL url = new URL(siteInfoBean.getSSiteURL()); Rv9jLH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i,*m(C@F}
httpConnection.setRequestProperty("User-Agent","NetFox"); T2<%[AF0
4\&Y;upy+
B F<u3p??
int responseCode=httpConnection.getResponseCode(); k*fU:q1
if(responseCode>=400) +m%%Bz>
{ hk4t #Km
processErrorCode(responseCode); ? /z[Jx.
return -2; //-2 represent access is error ?$109wZ:9
} |} b+$J
R\3a Sx L
tj@(0}pi4
String sHeader; ZK^cG'^2|
>[|N%9\
c]ARgrH-
for(int i=1;;i++) X n!mdR
{ !="q"X/*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -Y/i h(I^
//Utility.log(in.readLine()); 70c]|5
sHeader=httpConnection.getHeaderFieldKey(i); U*$P"sS`
if(sHeader!=null) $C\ETQ@
{ OY`B{jV-
if(sHeader.equals("Content-Length")) &su'znLV
{ Z*co\ pW
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !Rl|o^Vw>{
break; zg<-%r'$
} ^)gyKl:E'
} ^_bG{du
else dyWp'vCQs\
break; ^b+>r
} )FQ"l{P
} w_56y8Pd4
catch(IOException e){e.printStackTrace ();} QE(.w dHP
catch(Exception e){e.printStackTrace ();} AYA{_^#+3
MJ)lZ!KZ
H>EM3cFU
Utility.log(nFileLength); K4!-%d$
}~I!'J#)
>s{I@#9
return nFileLength; XX~vg>3_
} V|MGG
fkzSX8a9}
k <oB9J
//保存下载信息（文件指针位置） BkB>eE1)Ea
private void write_nPos() Wm}c-GD
{ 6^"QABc
try{ t_3j_`
output = new DataOutputStream(new FileOutputStream(tmpFile)); %hnBpz
output.writeInt(nStartPos.length); c1'@_Is
for(int i=0;i<nStartPos.length;i++) o{s2T)2
{ +NPL.b|
// output.writeLong(nPos); F<* /J]
output.writeLong(fileSplitterFetch.nStartPos); &F&`y
output.writeLong(fileSplitterFetch.nEndPos); QQ3<)i
} O^@8Drgc
output.close(); *DF3juf~
} I@'[>t
catch(IOException e){e.printStackTrace ();} [A-_?#cZ
catch(Exception e){e.printStackTrace ();} a$My6Qa#
} ]nTeTW
d/7fJ8y8
xo"GNFh!
//读取保存的下载信息（文件指针位置） 2Xt4Rqk$
private void read_nPos() Hy.u6Jt*/
{ F(G..XJQ
try{ }\"EI<$s
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); W>@ti9\t
int nCount = input.readInt(); Z,).)y#B
nStartPos = new long[nCount]; =A"Abmx|
nEndPos = new long[nCount]; ]at$ohS
for(int i=0;i<nStartPos.length;i++) E`IXBI
{ Q]k<Y
nStartPos = input.readLong(); hLO)-ueb
nEndPos = input.readLong(); [RyVR
} !vSI"$xd
input.close(); 66v,/#K
} Nm*(?1
catch(IOException e){e.printStackTrace ();} 9c>i>Vja!
catch(Exception e){e.printStackTrace ();} !7N:cx'Qy
} >ED;_L*_o
:R;w<Tbz"
Q dj(D\.
private void processErrorCode(int nErrorCode) xVxs~p1
{ \((iR>^|
System.err.println("Error Code : " + nErrorCode); hY"eGaoF"
} p*g Fr hm
/UCBoQ$/]
;wv[';J
//停止文件下载 RHF"$6EAFG
public void siteStop() ZbFD|~[ V
{ W{6QvQD8
bStop = true; 7)rQf{q7
for(int i=0;i<nStartPos.length;i++) BIx*t9wA
fileSplitterFetch.splitterStop(); &;BhL%)}
q*hn5K*
H,7='n7"
} k6tCfq;
} &[ })FI
//负责部分文件的抓取 GkAd"<B
**FileSplitterFetch.java jD S?p)&
*/ s9?mX@>h
package NetFox; ?8>a;0
]iV]7g8:
/`PYk]mJh
import java.io.*; `G\ qGllX
import java.net.*; *p{p.%Qs:
49qa
TegdB|y7O
public class FileSplitterFetch extends Thread { lu#a.41
Pf;OYWST
M\1CDU+*Ns
String sURL; //File URL W~ yb>+u
long nStartPos; //File Snippet Start Position RoqkT|#$
long nEndPos; //File Snippet End Position mR0`wrt
int nThreadID; //Thread's ID #qd!_oN
boolean bDownOver = false; //Downing is over '(]Wtx%9"
boolean bStop = false; //Stop identical }&v}S6T
FileAccessI fileAccessI = null; //File Access interface 6i/unwe!`)
Y>$5j}K
rz|T2K
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException X@~/.H5
{ !'$*Z(
this.sURL = sURL; zw<<st Bp
this.nStartPos = nStart; 4MC]s~n
this.nEndPos = nEnd; .][yH[F
nThreadID = id; z_c-1iXCW
fileAccessI = new FileAccessI(sName,nStartPos);//定位 l$u52e!7
} ]}`t~#Irz
eF3NyL(A
>?+Rtg|${
public void run() U&3!=|j
{ }s2CND
while(nStartPos < nEndPos && !bStop) ~<1s[Hu
{ J.iz%8
)CXlPbhY?
cqU6 Y*n
try{ pj%]t
URL url = new URL(sURL); shw?_#?1dy
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @3n!5XM{EE
httpConnection.setRequestProperty("User-Agent","NetFox"); veDv14
String sProperty = "bytes="+nStartPos+"-"; 091m$~r*
httpConnection.setRequestProperty("RANGE",sProperty); :$I"n\
Utility.log(sProperty); DN^+"_:TB
|QS|\8g{0V
8wWp+Hk
InputStream input = httpConnection.getInputStream(); -w+.'
//logResponseHead(httpConnection); T4x%3-4;
1F.._5_"]
:h@V,m Z
byte[] b = new byte[1024]; QFTiE1mGH
int nRead; /5 z+N(RFC
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) gLMb,buqC
{ :r{-:
nStartPos += fileAccessI.write(b,0,nRead); /[c_,G""
//if(nThreadID == 1) 2dz)rjdO,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U*nB= =
} Q]5_s{kiz
;)ay uS sQ
2Ys=/mh
Utility.log("Thread " + nThreadID + " is over!"); FqyxvL.
bDownOver = true; 2-m@-
//nPos = fileAccessI.write (b,0,nRead); e# Y{YtE
} WG,Il/
catch(Exception e){e.printStackTrace ();} e=XP4h
} ~v&Q\>'
} &NF$_*\E
i:Y5aZc/Ds
54{E&QvL8o
//打印回应的头信息 *~U*:>hS
public void logResponseHead(HttpURLConnection con) p` ~=v4;b
{ 8XVRRk
for(int i=1;;i++) m +A4aQ9
{ U:x;4
String header=con.getHeaderFieldKey(i); i&(1<S>P
if(header!=null) x7B;\D#`i/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^vm6JWwN0B
Utility.log(header+" : "+con.getHeaderField(header)); "T[BSj?E
else (Jb#'(~a
break; (e_<~+E
} 0fj C>AS
} {'alA
h@JX?LzZS
UvMkL
public void splitterStop() |FFz $'8)
{ _{):w~zi
bStop = true; +DQUL|\
} G>?kskm
^EN )}:%Z
{Zw;<1{E
} +hKU]DP2;
3AENY@*
M8:i]
/* [$K8y&\L
**FileAccess.java D]>Z5nr |
*//文件访问(定位，写) .[eC w
package NetFox; K:9AP{+
import java.io.*; Rkg)yme!N
x?A<X2
bD/ZKvg
public class FileAccessI implements Serializable{ o6w8Y/VPu
tf54EIy5Y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9:g]DIL
RandomAccessFile oSavedFile; \^pc"?Rc
long nPos; / j "}e_Q
mc`Z;D/mt
MrUjqv6a[
public FileAccessI() throws IOException myVa5m!7Q
{ i@D4bd9lR
this("",0); G*_]Lz(N
} |_g7k2oLY
\7h>9}wGf
]jI<Js*F
public FileAccessI(String sName,long nPos) throws IOException a0k;way
{ J9;fqQCt
oSavedFile = new RandomAccessFile(sName,"rw"); g/68& M
this.nPos = nPos; @J>JZ7m]\
oSavedFile.seek(nPos); Uu*iL< `
} K:XP;#OsP
6DU(KYN
?vbAaRg50s
public synchronized int write(byte[] b,int nStart,int nLen) =rZ'!Pa
{ wjH1Ombt
int n = -1; 7. $wK.
try{ <-' !I&
oSavedFile.write(b,nStart,nLen); A4rMJ+!5
n = nLen; cR!M{U.q
} a-S tOO5s
catch(IOException e) IS!OO<
{ ZDL1H3;R
e.printStackTrace (); b{aB^a:f=L
} yEjiMtQll]
2[(~_VJ
w-R.)
return n; nql9SQ'\\
} w oIZFus
=Yl ea,S
N.q*jY=X|
} .`_iWfK
LjGZp"&{
|/xx**?
/* $mAC8a_Zu
**SiteInfoBean.java PCL ;Z
*/ sG_/E-%5'
package NetFox; XC;Icr)
{Ak 4GL
'oY#a9~Z{
public class SiteInfoBean { VoUo!t:(+
%GY'pQz
OE0G*`m
private String sSiteURL; //Site's URL Wq+GlB*
private String sFilePath; //Saved File's Path /i27F2NQm
private String sFileName; //Saved File's Name u_+iH$zA
private int nSplitter; //Count of Splited Downloading File AIn/v`JeX
6|B9kh}
R3a}YwJFXF
public SiteInfoBean() [PUu9rz#
{//nSplitter的缺省值为5 M!i|,S
//default value of nSplitter is 5 a9p:k ]{
this("","","",5); $Z;/Sh
} a,S;JF)v
Mth:V45G|
8 I_
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4P1}XYD-2
{ ^Z;zA@[wt
sSiteURL= sURL; mgVYKZWL-i
sFilePath = sPath; $qYP|W
sFileName = sName; @>VVB{1@,]
this.nSplitter = nSpiltter; jMTM:~0N
, p~1fB-/
.S-)
} KfBT'6t
:zKMw=
}kr?+)wB
public String getSSiteURL() U7D!w$4
{ xR3$sA2
return sSiteURL; u)<s*jk
} Pb8@owG8
kq5X<'MM9N
_7;:*'>a4
public void setSSiteURL(String value) $+7uB-KsU
{ n:`f.jG |
sSiteURL = value; m?<E >-bI
} %Rn*oV
?BfE*I$\h
+K'Hr:(
public String getSFilePath() %;dj6):@
{ 2NMs-Zs
return sFilePath; 18Y#=uH}
} f2;.He
=f!clhO
"}V_.I*+
public void setSFilePath(String value) c?N,Cd~q
{ Wy%FF\D.Y
sFilePath = value; 5owK2
} jD${ZIv
xHMFYt+0$G
v&bG`\!
public String getSFileName() G[1\5dK*uR
{ bf|ePGW?
return sFileName; A,BYi$
} f}J(nz>Sh
)U=]HpuzI
J ZkQ/vp(
public void setSFileName(String value) Nte$cTjX
{ @$~IPg[J
sFileName = value; -Caj>K
} K{{_qFj@<y
*~>p;*
GbclR:G
public int getNSplitter() ^H&U_
{ $rI 1|;^
return nSplitter; ^sB0$|DU
} 15hqoo9!
r0 )ne|&Hp
a eeor
public void setNSplitter(int nCount) 3ye
{ QeG9CS)E}j
nSplitter = nCount; 1"L"LU'
} ( *Xn"o
} &iVdqr1,
P.qzP/Ny
a5GLbanF
/* yji[Yde;|
**Utility.java H=Ilum06
*/ !TJ,:c]4{!
package NetFox; CF2Bd:mfZ
S.)Jp-&K
c%J6!\
public class Utility { o]Rlivahm
4G?^#+|^
eM:J_>7t
public Utility() ANy*'/f
{ Ph1XI&us9
=y4dR#R(\
hU8Y&R)=9
} 52dD(
8&)v%TX
//线程睡眠 8s@N NjV
public static void sleep(int nSecond) LWN{
{ Wc[,kc
try{ )&Oc7\J,
Thread.sleep(nSecond); /v8Q17O?e
} RhH1nf2UR
catch(Exception e) lGl'A}]#$
{ 3/@z4:p0R
e.printStackTrace (); %,kP_[!>Q
} ]~KLdgru_
} ^AS\a4`/
b}3"v(
//日志 S{rltT-
public static void log(String sMsg) VN0We<\Z
{ $'498%K2
System.err.println(sMsg); _U<fS
} d9#Vq=H /
:TH cI;PG8
ej`%}e%2
public static void log(int sMsg) hfaU-IPcFX
{ GQqGrUQ*}
System.err.println(sMsg); `hi=y BO
} ^dHQ<L3.*
} Y$ys4X
0=j }`
[1VA`:?W
/* =?<WCR C*
**TestMethod.java H\67Pd(Z6
*/ |h>PUt@LL
package NetFox; h:YD$XE
;]>kp^C#
n|w+08c"
public class TestMethod { )/H;5 cn
*qd:f!Q3
~RhUg~o
public TestMethod() GXtMX ha,
{ ///xx/weblogic60b2_win.exe M&Ka^h;N
try{ \<4N'|:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;b$P*dSG}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); H_DCdUgC'
SiteFileFetch fileFetch = new SiteFileFetch(bean); {PHH1dC{
fileFetch.start(); `8:)? 0Ez
} zUfq.
catch(Exception e){e.printStackTrace ();} H U|.5tP
3S0.sU~_U
Kg[OUBv
} nw+~:c
9%!h/m>rW
/{i~CGc;"
public static void main(String[] args) ~MC|
{ 3o<d=@`r
new TestMethod(); _bFUr
} :t}\%%EbmE
} Q]:O#;"<
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