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)); 289teU
} rCqcl
for(int i=0;i<nEndPos.length-1;i++) i{TErJ{}e
{ W#!![JDc
nEndPos = nStartPos[i+1]; tep_g4CQR_
} X+"8yZz3?
nEndPos[nEndPos.length-1] = nFileLength; pv8"E?9,k
} ?<VahDBS+A
} WzYy<
[Dd?c,5AD
9NLO{kN
//启动子线程 f@lRa>Z(Fm
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; gK7j~.bb"
for(int i=0;i<nStartPos.length;i++) <_&tP=h
{ %tiFx:F+
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j4RM'_*G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Ym6zNb8 bQ
nStartPos,nEndPos,i); Rr+Y::E
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); . fq[>zG'&
fileSplitterFetch.start(); @*jd.a`
} x"0*U9f
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "pTyQT9P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [X[d`@rXv
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (5Q,d [B
nEndPos = " + nFileLength); J/Ki]T9
// fileSplitterFetch[nPos.length-1].start(); /Y|oDfv
6'd=% V
vQCRs!A
//等待子线程结束 =BO} hk
//int count = 0; UV8,SSDTV
//是否结束while循环 aW$(lf2;
boolean breakWhile = false; 1!<k-vt
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<*u[<
while(!bStop) hp?hb-4l
{ * bx%hX
write_nPos(); /N(L52mz
Utility.sleep(500); DP`$gd
breakWhile = true; 9Cbf[\J!bq
n)$T zND
}|>mR];
for(int i=0;i<nStartPos.length;i++) OpeK-K
{ >en,MT|
if(!fileSplitterFetch.bDownOver) sS#Lnj^`%
{ 16=tHo8|
breakWhile = false; qXO@FW]
break; \P% E1c#
} X,d`-aKO\y
} bf]W_I]B
if(breakWhile) b}63?.M{
break; 7kapa59
{iiHeSD
dX|(n.}
//count++; </0@7
//if(count>4) apQ` l^
// siteStop(); }Jkz0JY~
} & xOEp
d;UP|c>2
ZnDI J&S
System.err.println("文件下载结束！"); t>;u;XY!;
} !ckmNE0
catch(Exception e){e.printStackTrace ();} Cw"Y=`
} ]H8,}
Z^w11}
k@r%>Ul@
//获得文件长度 R/5aIh
public long getFileSize() ~_^#/BnAl
{ pj?wQ'
int nFileLength = -1; D9`J||]E
try{ WO{V,<;
URL url = new URL(siteInfoBean.getSSiteURL()); )`5kfj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8,Iil:w
httpConnection.setRequestProperty("User-Agent","NetFox"); [>l2E
!#P|2>>u
)i@j``P
int responseCode=httpConnection.getResponseCode(); kc#<Gr&Z&
if(responseCode>=400) KICy! "af
{ f S-(Kmh
processErrorCode(responseCode); RzG7Xr=t
return -2; //-2 represent access is error Q; DN*
} LJ7Qwh_",
C" vj#Tx
O_@
String sHeader; +dd\_\
-olD!zKS
20glz(
for(int i=1;;i++) HPM ggRs
{ CMk0(sztU_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8%-+@\=
//Utility.log(in.readLine()); pRS+vV3
sHeader=httpConnection.getHeaderFieldKey(i); g *}M;"
if(sHeader!=null) iDp'M`(6h
{ @uru4>1_dy
if(sHeader.equals("Content-Length")) t As@0`x9
{ t+C9QXY
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); vFuf{ @P
break; ID+o6/V8
} j*2Q{ik>J
} 9='a9\((mH
else "`Y.N$M`k
break; 6:Eu[PE~w
} Nr24Rv
} 1;O%8sp&
catch(IOException e){e.printStackTrace ();} \^=Wp'5R
catch(Exception e){e.printStackTrace ();} rof&O
<G d?,}\
tl.I:A5L
Utility.log(nFileLength); R.KqTEs<k
s{IXth6
]xJ5}/
return nFileLength; 8=XfwwWHy<
} g.3 . C?
879x(JII
gDY+'6m;
//保存下载信息（文件指针位置） wD(1Sr5n
private void write_nPos() %Pl 7FHfB
{ \?n4d#=$o
try{ 3I|&}+Z6
output = new DataOutputStream(new FileOutputStream(tmpFile)); hN(sz
output.writeInt(nStartPos.length); vkFfHzR$
for(int i=0;i<nStartPos.length;i++) U%E6"Hg
{ B.:DW3
// output.writeLong(nPos); F_KPhe$
output.writeLong(fileSplitterFetch.nStartPos); m|tE3UBNv
output.writeLong(fileSplitterFetch.nEndPos); (``EBEn
} eh`sfH
output.close(); y^M~zOe
} HiTn5XNf
catch(IOException e){e.printStackTrace ();} )9(Mt_
catch(Exception e){e.printStackTrace ();} () l#}H`m
} UkO L7M
`R}q&|o7<
^]iIvIp
//读取保存的下载信息（文件指针位置） ; E Nhy
private void read_nPos() ('SA9JG
{ H.sYy-_]F
try{ ?kOtK
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .f+ul@o
int nCount = input.readInt(); VBHDI{HzRv
nStartPos = new long[nCount]; 43i@5F]
nEndPos = new long[nCount]; +9 Uo<6}
for(int i=0;i<nStartPos.length;i++) ROWb:tX}
{ PS*=MyNa
nStartPos = input.readLong(); P[;<,U;'HO
nEndPos = input.readLong(); (:JX;<-
} zli@XZ#
input.close(); -2)6QKh~D
} %t*_Rtz\o
catch(IOException e){e.printStackTrace ();} j3<|X
catch(Exception e){e.printStackTrace ();} P>*B{fi^
} ]u;Ma G=;
SGuR-$U`)
^qn,b/>L
private void processErrorCode(int nErrorCode) <=]wh|D
{ .XD.'S
System.err.println("Error Code : " + nErrorCode); 4Dd@&N
} p};B*[ki
PL+j;V(<
B%~hVpm,eM
//停止文件下载 d0@&2hO
public void siteStop() jFa{h!
{ ; O6Ez-"
bStop = true; JG]67v{F
for(int i=0;i<nStartPos.length;i++) n^HKf^]
fileSplitterFetch.splitterStop(); xq U@87[_
{_ &*"bK
NJ^H"FLS:
} 0^5*@vt
} &#keI.,
//负责部分文件的抓取 ;zMZ+GZ?;+
**FileSplitterFetch.java : h"Bf@3
*/ z0@{5e$#Y
package NetFox; Y|*a,H"_
/< OoZf+[
Gr1WBYK
import java.io.*; hKG)* Q
import java.net.*; ]c67zyX=%
*,hg+?lZ
4,nUCT
public class FileSplitterFetch extends Thread { 2J>v4EWC
;9WS#>o
=vd9mb-
String sURL; //File URL !Vtj:2PQL
long nStartPos; //File Snippet Start Position yvQRr75
long nEndPos; //File Snippet End Position m$ubxI)
int nThreadID; //Thread's ID SxAZ2|/-
boolean bDownOver = false; //Downing is over !foiGZ3g
boolean bStop = false; //Stop identical ~>j5z&:&
FileAccessI fileAccessI = null; //File Access interface z0yPBt1W
&bIE"ZBjt
v;%>F)I
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;ui=7[Us
{ GKT^rc-YT-
this.sURL = sURL; vs*Q {
this.nStartPos = nStart; cft'%IEs
this.nEndPos = nEnd; w=|"{-ijo
nThreadID = id; Te\i;7;4u
fileAccessI = new FileAccessI(sName,nStartPos);//定位 bhqV2y*'
} +dw=)A#/
%^zGM^PD
+\Zr\fOe|%
public void run() jDyG~de
{ <i!:{'%
while(nStartPos < nEndPos && !bStop) ZQ MK1
{ xE0'eC5n^
A9D vU)1
h)~i?bq!/
try{ 1kX>sajp~
URL url = new URL(sURL); :!cNkJa
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0q!
httpConnection.setRequestProperty("User-Agent","NetFox"); dXBXV>rbB
String sProperty = "bytes="+nStartPos+"-"; ;7 F'xz"
httpConnection.setRequestProperty("RANGE",sProperty); 3|Vh[iAa\
Utility.log(sProperty); $-J=UT2m
s|q]11r+H
n0T>sE-9
InputStream input = httpConnection.getInputStream(); axpn*(yE
//logResponseHead(httpConnection); !!\OB6
9 M<3m
01brl^5K
byte[] b = new byte[1024]; 5 `Mos
int nRead; f,s1k[w/;
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Vs:x3)m5j
{ 1>"Yw|F-|3
nStartPos += fileAccessI.write(b,0,nRead); |B` mWZ'"
//if(nThreadID == 1) NH$!<ffz
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `#Yv(a2TY
} 3<:m;F*#
:5 zXW;s
Y`tv"v2
Utility.log("Thread " + nThreadID + " is over!"); J Gpy$T{t
bDownOver = true; K7jz*|2
//nPos = fileAccessI.write (b,0,nRead); dJYW8pcKT
} vf&Sk`
catch(Exception e){e.printStackTrace ();} q>^x,:L
} E$?:^ausu
} 4w)aAXK
A2xfNY<
hp<NVST
//打印回应的头信息 IFd2r;W8
public void logResponseHead(HttpURLConnection con) :}[RDF?
{ 08pG)_L
for(int i=1;;i++) #1#?k
{ l^WPv/}?
String header=con.getHeaderFieldKey(i); YS|Ve*t(L=
if(header!=null) &|j^?ro6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _go1gf7
Utility.log(header+" : "+con.getHeaderField(header)); {r.yoI4e
else B?|url6h
break; 6t0-u~
} E5EAk6
} F/(z3Kf
_1sjsGp>
%Q2<bj]
public void splitterStop() l^"HcP6
{ >qT4'1S*g
bStop = true; bFt$u]Yvo
} Kz`g Q|S
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qL 0{w7
} {:!CA/0Jx
D$OUy}[2`.
q/N1q&
/* cf7UV6D g
**FileAccess.java re-;s
*//文件访问(定位，写) 4#c-?mh_
package NetFox; DGY?4r7>y
import java.io.*; ='"hB~[
xD|CQo}:
<Jwx|
public class FileAccessI implements Serializable{ U<"@@``+N
cIJqF.k
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 x_K8Gr#Z0
RandomAccessFile oSavedFile; ^o@N.+`&<
long nPos; S~+er{,ht4
=Co[pt
8U$(9X
public FileAccessI() throws IOException %x2_njDd
{ Qv`Lc]'
this("",0); j4fv-{=$
} G7yR&x^
%0<-5&GE
m\];.Da
public FileAccessI(String sName,long nPos) throws IOException f'>270pH
{ HT: p'Yyi
oSavedFile = new RandomAccessFile(sName,"rw"); }bZcVc2
this.nPos = nPos; f#mcWL1}
oSavedFile.seek(nPos); 4*vV9*'!
} #,4CeD|(D,
<PayP3E
A3Lfh6O
public synchronized int write(byte[] b,int nStart,int nLen) 0M=U>g)
{ 6_.K9;Gd
int n = -1; NGYUZ\m
try{ (r]3tGp
oSavedFile.write(b,nStart,nLen); 4-wCk=I
n = nLen; 9AGf4tuy
} 0';U3:=i,
catch(IOException e) 0<{zW%w
{ qyx '
e.printStackTrace (); JTw3uM, e
} 9t1aR*b&@
L#|,_j=9
"{&?t}rj+
return n; Bn5O;I13
} e9 `n@
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=DT7]fU
} "0&+`7
-ST[!W V
#:5vN-9?
/* )U~,q>H+ %
**SiteInfoBean.java Rpi@^~aPE
*/ E[Rd=/P6
package NetFox; ;ZSJ-r
\"X<\3z2
%O!~!'
public class SiteInfoBean { :JEzfI1
n'&Cr0{
B}(+\Q$I
private String sSiteURL; //Site's URL $GR 3tLzK:
private String sFilePath; //Saved File's Path %DKQ
private String sFileName; //Saved File's Name 6^Q Bol
private int nSplitter; //Count of Splited Downloading File BfcpB)N&.K
qNH= W?T8.
+ \DGS
public SiteInfoBean() ZP]l%6\.
{//nSplitter的缺省值为5 7<ZP(I5X
//default value of nSplitter is 5 ?0{8fGM4
this("","","",5); 78iu<L+If
} Yb~[XS |p
?_!} lg
";&5@H|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) w=]bj0<A=
{ c']3N
sSiteURL= sURL; u Z(vf
sFilePath = sPath; uh][qMyLM
sFileName = sName; &at^~o
this.nSplitter = nSpiltter; {GTOHJ2
xcF:moL
`<0{U]m
} tML[~AZh
J<<Ph
H\zV/1~Y
public String getSSiteURL() wNHvYulI
{ WB:NV=&^
return sSiteURL; wRa$b
} LQ7.RK
+zU[rhMk'
]dx6E6A,
public void setSSiteURL(String value) 'Mfn:n+
{ QO0#p1fom'
sSiteURL = value; W+F^(SC\
} O%1X[
f.Uvf^T}2
N^)\+*tf1
public String getSFilePath() 5#DtaVz
{ @Kx@ 2#~b
return sFilePath; !9B`
} M<4tjVQ6
+@U}gk;#c
-HE@wda
public void setSFilePath(String value) |f:1Br
{ x&ngCB@O
sFilePath = value; 7j9X<8*
} ?89K [D|
F5hOKUjv
Wfw6(L
public String getSFileName() SuO@LroxTB
{ jD`p;#~8
return sFileName; mbij& 0
} ODggGB`H`
wM]j#
*dTI4k
public void setSFileName(String value) 4Jf6uhaE
{ F2B9Q_>P
sFileName = value; ^Yz.}a##w2
} ~{8X$xs
[m}58?0~x
>+9f{FP 9
public int getNSplitter() l"C)Ia&/
{ ^lt;K{
return nSplitter; MPexc5_
} K&\3j-8^
H{XD>q.
QSaJb?I
public void setNSplitter(int nCount) mYE8]4
{ g[#4`Q<.
nSplitter = nCount; O%>FKU>(?
} +&U{>?.u
} ~O;'],#Co
3;N+5*-
B!;qz[]I
/* YgeU>I|v
**Utility.java y[pU8QSt
*/ Sh]g]xR
package NetFox; "#3p=}]
Qd{h3K^hlu
{m<NPtp910
public class Utility { GC<zL}
8|*=p4_fn
M_ GN3
public Utility() ,.g9HO/R1
{ B?-~f^*,jG
x+X^K_*
&ND8^lR=Y;
} _LOV&83O(
)(aj
//线程睡眠 K<3$>/|
public static void sleep(int nSecond) #Q6.r.3@x
{ A18&9gY
try{ 7p!w(N?s
Thread.sleep(nSecond); C4`u3S
} ,o_Ur.UJ
catch(Exception e) knPo"GQW
{ z1WF@Ej
e.printStackTrace (); h|DKD.
} !R`)S7!
} QIcg4\d%s
gOE3x^X*{
//日志 6?CBa]QG
public static void log(String sMsg) _BA2^C':c{
{ 3 E~d
System.err.println(sMsg); ? 7H'#l
} :Hn*|+'
U'Xw'?Uj
rLy<3
public static void log(int sMsg) '%D$|)
{ }`SXUM_sD`
System.err.println(sMsg); Yy_o*Ozq
} n1Y3b~E?E
} c T[.T#I
@ k`^Z5tN
=36e&z-#
/* N~w4|q!]
**TestMethod.java +Y:L4`
*/ wl*"Vagb
package NetFox; g.cD3N
CUS^j
2Sq+w;/
public class TestMethod { l9 K 3E<g
c1,dT2:=
jv"^_1
public TestMethod() 49BLJ|:P?
{ ///xx/weblogic60b2_win.exe q$;'Fy%oy
try{ Tath9wlv6;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ice7J2r_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); OfR\8hAY
SiteFileFetch fileFetch = new SiteFileFetch(bean); ic"n*SZa
fileFetch.start(); R/yOy^<
} 7Y8B \B)w
catch(Exception e){e.printStackTrace ();} V!'N:je
3,snx4q (
e<wRA["
} 4E Hb
xELnik_L2
$J~~.PUXQ
public static void main(String[] args) A0NNB%4|/
{ >};6>)0
new TestMethod(); ]g>@r.Nc
} YzcuS/~x
} "4{_amgm&<
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