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)); 1,%#O;ya
} `aO@N(
for(int i=0;i<nEndPos.length-1;i++) RF,=bOr19
{ t]u(jX)
nEndPos = nStartPos[i+1]; 7tf81*e
} T;4gcJPn"M
nEndPos[nEndPos.length-1] = nFileLength; !7Yt`l$$z
} lt2Nwt0bv
} ^;Hi/KvM\
3G%XG{dg
!Z+*",]_
//启动子线程 5ykk11!p$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; U'h[{ek
for(int i=0;i<nStartPos.length;i++) )L(d$N=Bd
{ 'n>3`1E,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J1c&"Oh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), bzj!d|T`
nStartPos,nEndPos,i); `:bvuc(
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #v~S",*.f
fileSplitterFetch.start(); Q#J>vwi=
} >F\rBc&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >arO$|W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7n\j"0z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (4{@oM#H6
nEndPos = " + nFileLength); ?;.1fJU>
// fileSplitterFetch[nPos.length-1].start(); sjkKaid
'^-4{Y^2E
RBK>Lws6
//等待子线程结束 cDQw`ORP*g
//int count = 0; G0 nH Z6
//是否结束while循环 yqVaA 'w5
boolean breakWhile = false; *OGXu07 !
@E"+qPp.3
;@7#w
while(!bStop) p^zEfLTU
{ %<ptkZK#
write_nPos(); ^7s6J{<
Utility.sleep(500); %)6:eIS
breakWhile = true; zfr(dQ
3R:7bex
QqFfR#
for(int i=0;i<nStartPos.length;i++) xV n]m9i
{ Cs1%g
if(!fileSplitterFetch.bDownOver) Nz>E#.++
{ a`@<ZsR
breakWhile = false; jB/q1vFO
break; X_tW#`
} o+)LcoPu
} kq1M<lk
if(breakWhile) |q!2i
break; N5w]2xz!
)q]j?Z.
(g)lv)4P
//count++; G|PIH#
//if(count>4) R0YC:rAt
// siteStop(); Dho^^<`c+
} /4-eoTxy
c@o/Cv
dV2b)p4J
System.err.println("文件下载结束！"); EhP&L?EL
} W-]yKSob
catch(Exception e){e.printStackTrace ();} |E_+*1lq.
} r/q1&*T
cV,03]x
YZ%f7BUk
//获得文件长度 fssL'DD
public long getFileSize() 4KSP81}/\
{ $OFFH[_z
int nFileLength = -1; XUqE5[O%
try{ jXDzjt94J
URL url = new URL(siteInfoBean.getSSiteURL()); Uhx2 _
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7dg 5HH
httpConnection.setRequestProperty("User-Agent","NetFox"); nxh/&%
C@?e`=9(
%`T^qh_dE
int responseCode=httpConnection.getResponseCode(); *(SBl}f4l
if(responseCode>=400) A$"$`)P!
{ #u=O 5%.
processErrorCode(responseCode); Ff#N|L'9_
return -2; //-2 represent access is error fN*4(yw
} ,YMdXYu`s
k#=leu"I
u,SX`6%
String sHeader; yA>p[F
knK=ENf;e
;'18
for(int i=1;;i++) _8b>r1$
{ vVN[bD<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "6NNId|Y
//Utility.log(in.readLine()); v!'@NW_
sHeader=httpConnection.getHeaderFieldKey(i); {u=\-|t
if(sHeader!=null) n$![b_)*
{ DwrCysIK
if(sHeader.equals("Content-Length")) ?e_}X3{
{ R?9Plzt5
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K{w=qJBM
break; k;:u| s8NS
} F=T.*-oS3
} eg~^wi
else pu)9"Ad[ G
break; BK\~I
} "$"mWF-
} <$3nD b-
catch(IOException e){e.printStackTrace ();} . ;@)5"
catch(Exception e){e.printStackTrace ();} !RUo:b+
Lp]C![\>U
(uK), *6B
Utility.log(nFileLength); 1]3bx N
4a\+o]
]jY)M<:J4
return nFileLength; n]{}C.C=
} |b;M5w?
6C51:XQO
oD}FJvV
//保存下载信息（文件指针位置） j83Y'VJJC
private void write_nPos() =$zr t
{ }]GK@nn7
try{ 5sCky)N
output = new DataOutputStream(new FileOutputStream(tmpFile)); "u]Fl+c
output.writeInt(nStartPos.length); 8}0y)aJ
for(int i=0;i<nStartPos.length;i++) wG[l9)lz
{ Y(yJ|y&
// output.writeLong(nPos); i\z0{;f|GX
output.writeLong(fileSplitterFetch.nStartPos); PaeafL65=
output.writeLong(fileSplitterFetch.nEndPos); adE0oXQH"
} IlL
output.close(); v%7JZ<I'A
} IguG03:.N
catch(IOException e){e.printStackTrace ();} PWD]qtr
catch(Exception e){e.printStackTrace ();} :8L61d2(
} gV44PI6h
R]sjG<
GQ)cUrXQz
//读取保存的下载信息（文件指针位置） <:7e4#
private void read_nPos() ;3}b&Z[N]
{ d@4=XSj
try{ KIY_EE$?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8=Y|B5
int nCount = input.readInt(); 43Uy<%yb>}
nStartPos = new long[nCount]; VQ;- dCV
nEndPos = new long[nCount]; r$eL-jQmn
for(int i=0;i<nStartPos.length;i++) 3K:Xxkk
{ XBt0Ez
nStartPos = input.readLong(); 5h^qtK
nEndPos = input.readLong(); (9_e>2_
} F%$Ws>l
input.close(); 00wH#_fm
} uOUw8
catch(IOException e){e.printStackTrace ();} 2}\sj'0&
catch(Exception e){e.printStackTrace ();} ZS>/ 5
} n?fC_dy
I%*Zj,>
IX3yNTW"L
private void processErrorCode(int nErrorCode) um;U;%?Q
{ 5P2FNUKL
System.err.println("Error Code : " + nErrorCode); 4qR Q,g{$T
} ;ypO'
54_m{&hb
=|zLr"
//停止文件下载 o@~gg*
public void siteStop() 2qR@:^
{ TEyPlSGG
bStop = true; #{`NJ2DU]
for(int i=0;i<nStartPos.length;i++) {"(|oIo{
fileSplitterFetch.splitterStop(); BU\NBvX$
cJ{P,K
-;.fU44O[#
} }(O kl1
} 1L9 <1
//负责部分文件的抓取 m,fr?d/;
**FileSplitterFetch.java QncS&
*/ |8+rUFkU8
package NetFox; L| qY
X KeK;+
w8Vzx8
import java.io.*; md_s2d
import java.net.*; p)]^>-L
0d)n}fm
uV\#J{'*
public class FileSplitterFetch extends Thread { 3VgH*vAU}
?Ir6*ZyY
\srOU|
String sURL; //File URL $jL.TraV7
long nStartPos; //File Snippet Start Position uty]-k
long nEndPos; //File Snippet End Position L)"w-,zy
int nThreadID; //Thread's ID [vJosbU;
boolean bDownOver = false; //Downing is over _\]UA?0
boolean bStop = false; //Stop identical cl8Mv
FileAccessI fileAccessI = null; //File Access interface w8zQDPVB%
:{imRa-
EE{%hGb
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException sAj$U^Gp
{ 1x8]&
this.sURL = sURL; (VRnv
this.nStartPos = nStart; a[#BlH
this.nEndPos = nEnd; Ho9*y3]
nThreadID = id; ~_6rD`2cJ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1O{67Pf
} RT9|E80
@72G*u\Wz
'a9.JS[pj
public void run() u(qpdG||7
{ Y*Rqgpu $
while(nStartPos < nEndPos && !bStop) eVJL|uI|
{ P=g+6-1
KJ |1zCM
oOvbel`;
try{ \8H"lcj:
URL url = new URL(sURL); oOw"k*,h:S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Cq'r 'cBZ
httpConnection.setRequestProperty("User-Agent","NetFox"); lTNkmQ
String sProperty = "bytes="+nStartPos+"-"; -UE-v
httpConnection.setRequestProperty("RANGE",sProperty); |MGw$
Utility.log(sProperty); aUQq<H'R
z(` kWF1<
OTm"Iwzu@
InputStream input = httpConnection.getInputStream(); Ds$;{wl#x
//logResponseHead(httpConnection); *9 xD]ZZF
|9@;Muq;
83|/sWrvh
byte[] b = new byte[1024]; @ZWKs
int nRead; /$Jh5Bv
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !o7.L%S
{ Iu]P^8
nStartPos += fileAccessI.write(b,0,nRead); l$NEx0Dffz
//if(nThreadID == 1) e;v2`2z2
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3J{'|3x
} z5zm,Jw
P#]jPW
8;@eY`0(
Utility.log("Thread " + nThreadID + " is over!"); 4+Kc
bDownOver = true; {M5IJt"{4b
//nPos = fileAccessI.write (b,0,nRead); dzap]RpB
} ^8*.r+7p
catch(Exception e){e.printStackTrace ();} P=GM7
} g [K8G
} EJsb{$u
""=Vt]
NiF*h~q
//打印回应的头信息 n~)%ou
public void logResponseHead(HttpURLConnection con) (TsgVq]L
{ C.Yz<?;S
for(int i=1;;i++) 0 $r{h}[^c
{ 5VS<I\o}
String header=con.getHeaderFieldKey(i); R8]bi|e)
if(header!=null) t `oP;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); aeIR}'H|
Utility.log(header+" : "+con.getHeaderField(header)); x3 <Lx^;
else G#>nOB
break; s4\2lBU?
} -u(#V#}OV?
} KA7nncg;,
yCVBG
:nn'>
public void splitterStop() xMu6PM<l
{ )XWL'':bF
bStop = true; N[%IrN3
} Ex{]<6UAu
`K.yE0^i
o>h>#!e
} G5Nub9_*X
y+_U6rv[
4ai3@f5
/* W3#L!&z_wK
**FileAccess.java 5Dd;?T>
*//文件访问(定位，写) Z(cgI5Pu
package NetFox; VEk|lX;2
import java.io.*; .)Q'j94Q
>jIc/yEYKI
NUseYU``
public class FileAccessI implements Serializable{ d#su
6/)A6Tt
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Cq=c'(cX
RandomAccessFile oSavedFile; Yi3DoaS;"
long nPos; kBkhuKd)V
+=QboUN
u&:jQ:[
public FileAccessI() throws IOException YZd4% zF
{ x1Uj4*Au
this("",0); Zv_<*uzKZ
} x$t=6@<]
8w4.|h5FP
9(Z)c
public FileAccessI(String sName,long nPos) throws IOException wS*UXF&f
{ bk|>a=o3
oSavedFile = new RandomAccessFile(sName,"rw"); I[/u5V_b'
this.nPos = nPos; H Zc;.jJ
oSavedFile.seek(nPos); iD9GAe}x
} "Y6f.rB
!Wk "a7
]#;JPO#*
public synchronized int write(byte[] b,int nStart,int nLen) zB4gnVhus|
{ juM?y'A
int n = -1; &j$k58mX
try{ !^%b|=[
oSavedFile.write(b,nStart,nLen); %%#zO Z
n = nLen; 5E]I
} %NuS!v>
catch(IOException e) Sn0 Gw
{ A-kI_&g\Og
e.printStackTrace (); +Z+]Tqo
} 2X:n75()
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j`bOJTBE
return n; QAr1U7{(.
} SExd-=G
F C"dQ
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} &( Z8G~h4
|o`TRqs
P+JYs
/* ;G?_^ 0
**SiteInfoBean.java Z^b1i`v
*/ R lv|DED$
package NetFox; S;= D/)[mr
D`+'#%%x
8"? t6Z;5
public class SiteInfoBean { AO/R2a(:
+%0+
8ARpjYZP
private String sSiteURL; //Site's URL Q~`n%uYg\{
private String sFilePath; //Saved File's Path 9d v+u6)
private String sFileName; //Saved File's Name "&An9H'
private int nSplitter; //Count of Splited Downloading File *v6'I-#
z}Q54,9m
H}d&>!\}F
public SiteInfoBean() nI-\HAX
{//nSplitter的缺省值为5 Gk<h_1WWK
//default value of nSplitter is 5 >zhbOkR9c
this("","","",5); tH$Z_(5
} 6HyQm?c>a
<)&;9C
3K{'~?mM
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Bb m1&d#
{ >n#Pq{7aF
sSiteURL= sURL; .Sm7na K
sFilePath = sPath; 1 #_R`(C{
sFileName = sName; /.vB /{2
this.nSplitter = nSpiltter; N[Fz6,ZG _
3ILEc:<0J
cu|{cy-
} jGId)f!)
6B&':N98
GSsot%B u"
public String getSSiteURL() ~"8b\oLW
{ ~%'M[3Rb
return sSiteURL; +~HL"Vv
} dQt]r
8uNq353
!pgkUzMW
public void setSSiteURL(String value) |iU#!+zY
{ `Q,03W#GJ%
sSiteURL = value; a *>$6H;
} Xfe,ZC)
hH>t
wTG6>l]H
public String getSFilePath() x5s Yo\
{ P)4SrqW_
return sFilePath; >%t"VpvR
} R'He(x
GC.
2!}5shB
public void setSFilePath(String value) sdrALl;w|
{ &W*9'vSm.
sFilePath = value; 7aS`SF
} yqZKn=1:
RCKb5p9
TX$j-TM'
public String getSFileName() #Fq6-]y1")
{ {eL XVNR7R
return sFileName; Y}QtgZEt
} YjAwt;%-D
re:=fC:t5A
y]+q mNw"+
public void setSFileName(String value) xwq {0jY
{ /g@!#Dt
sFileName = value; i.Yz)Bw
} _3.=| @L
\G:\36l
|4UW.dGHPo
public int getNSplitter() mGb,oj7l
{ @uApm~}
return nSplitter; 63 F@Ft
} Eu2@%2}P
;.+sz(:hm
I'm.+(1m,
public void setNSplitter(int nCount) WZ> }
{ Dm2&}{&K
nSplitter = nCount; 1$H*E~
} Z$"E|nRN
} qX>mOW^gT8
')zdI]@M
d?)k<!fJk
/* _XvSe]`f`
**Utility.java 5=(fuY3
*/ Y {a#2(xn
package NetFox; u[k0z!p_ c
DAa??/,x7
*Yj!f68
public class Utility { 9l<f?OzAO
~qekM>z
P :zZ
public Utility()
{ j#6@cO'`
2[zFKK
5FKb7
} Z#+lwZD
^VabXGzo#
//线程睡眠 h)7hk*I
public static void sleep(int nSecond) =MMU(0 E
{ /{il;/Vj
try{ O7vJ`K(!
Thread.sleep(nSecond); h'%iY6!fA
} _[M*o0[@W
catch(Exception e) Qu]F<H*Y|
{ ;&=c@>!xP#
e.printStackTrace (); vuN!7*d+
} B*B}eXUph
} 4E:kDl*@
NpqK+GO
//日志 $^~dqmE2,
public static void log(String sMsg) _!_%Afz
{ apmZ&Ab
System.err.println(sMsg); +9yV'd>U
} v@n0ma=
{5`=){
DNwqi"
public static void log(int sMsg) ?Pbh&!
{ o>~xrV`E
System.err.println(sMsg); PLoD^3uG)
} ]fiAV|'^
} U}hQVpP#
)a99@`L\P
T3H\KRe6
/* {_[\k^98>
**TestMethod.java t:$^iUrx
*/ Ct@OS227x
package NetFox; % XvJJ
7UnB]-:.
9IfeaoZZ4q
public class TestMethod { so=Ux2
KcPI,.4{
ny++U;qi
public TestMethod() T'8d|$X
{ ///xx/weblogic60b2_win.exe 85gdmla@9
try{ ';,Rq9-'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,;%F\<b
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); uz U2)n3y
SiteFileFetch fileFetch = new SiteFileFetch(bean); jc0Trs{Jf
fileFetch.start(); cI#! Y
} %0&c0vT
catch(Exception e){e.printStackTrace ();} KdN+$fe*g
v2K6y|6,
k z{_H`5.
} 0Tp,b (;n
3+~m9:9
L>@:Xo@
public static void main(String[] args) Fx!NRY_
{ g._`"c
new TestMethod(); &[#iM0;)W0
} lD+f{GR
} &GKtD)
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