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)); WDc2Qt
} O)NEt
for(int i=0;i<nEndPos.length-1;i++) \' (_r
{ H. UwM
nEndPos = nStartPos[i+1]; y1z<{'2x
} 3#o!K
nEndPos[nEndPos.length-1] = nFileLength; `oQ)qa_
} 8q*MhH>6I
} '#K:e
jkw:h0hX
# ~SuL3
//启动子线程 2gLa4B-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; J`}5bnFP
for(int i=0;i<nStartPos.length;i++) d1$3~Xl]
{ fZ!fwg$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), VU6nu4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^c",!Lp}{
nStartPos,nEndPos,i); Mr'P0^^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /Ud<4j-
fileSplitterFetch.start(); LnZzY0
} qd\5S*Z1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Cj^:8 ?%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Gu} `X23
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `|@#~
nEndPos = " + nFileLength); A;VjMfoB
// fileSplitterFetch[nPos.length-1].start(); <8#Q5
IH|PdVNtg
)QS4Z{)U
//等待子线程结束 uJ;7]
//int count = 0; 1d)wE4c=Z
//是否结束while循环 wO:!B\e
boolean breakWhile = false; f@U\2r
5A(zQ'6
CMI'y(GN
while(!bStop) -=_bXco}
{ P{2V@ <}
write_nPos(); o|#Mq"od
Utility.sleep(500); PR rf$& u
breakWhile = true; 2D|2/ >[
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b=[gK|fu
for(int i=0;i<nStartPos.length;i++) `;Qw/xl_N
{ Bc%A aZ0x
if(!fileSplitterFetch.bDownOver) e45gjjts
{ -WiOs;2~/
breakWhile = false; "[(&$I
break; py#`
} nd)Z0%xo
} P&PPX#%
if(breakWhile) {;.q?mj
break; ).aQ}Gwx^
$50rj
Uawf,57v<
//count++; 3k)W0]:|<
//if(count>4) zO#{qF+~;
// siteStop(); v^;-w~?3
} Q(@/,%EF
-<rQOPH%
Nu!(7
System.err.println("文件下载结束！"); !9GJ9ZEXM
} c`:hEQs
catch(Exception e){e.printStackTrace ();} m# #( uSh
} 0ox 8_l
p<>xqU
,nn5LQ|l.j
//获得文件长度 r(sQI# P
public long getFileSize() "-aak )7w
{ JNhHQvi\
int nFileLength = -1; HU[a b
try{ \~V ZY
URL url = new URL(siteInfoBean.getSSiteURL()); 9=,^^,q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Wn;B~
httpConnection.setRequestProperty("User-Agent","NetFox"); q-c9YOz_
Z9cg,#(D
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int responseCode=httpConnection.getResponseCode(); /Mk85C79
if(responseCode>=400) @**@W[EM
{ a& >(*PQ
processErrorCode(responseCode); ua$H"(#c
return -2; //-2 represent access is error >~O36q^w
} hw[jVx
+$]eA'Bh@
Nda,G++5(
String sHeader; $@m)8T
;8WgbR)ZLU
qyXx`'e
for(int i=1;;i++) !'uLV#YEZ
{ >r Nff!Ow
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Y|ONCc
//Utility.log(in.readLine()); diXb8L7B;
sHeader=httpConnection.getHeaderFieldKey(i); Fv!zS.)`
if(sHeader!=null) rBBA`Ut@F
{ y!6+jrI
if(sHeader.equals("Content-Length")) mHTZ:84
{ =)Z!qjf1U
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); f1R&Q
break; rNzsc|a:
} 1rhsmcE
} 1d49z9F
else j.C)KwelBS
break; @V$,H/v:
} C+{du^c$
} .ZSGnbJ
catch(IOException e){e.printStackTrace ();} GKPC9;{W
catch(Exception e){e.printStackTrace ();} qGndh
|12Cg>;j*n
g@WGd(o0)
Utility.log(nFileLength); a`}b'X:
y/'^r?
-9BKa~ DVQ
return nFileLength; m9*Lo[EXO
} \EH:FM}l,
u3{gX{so
Y-(),k_Q:
//保存下载信息（文件指针位置） (s?`*i:2
private void write_nPos() EZvB#cuL-
{ X]'Hz@$N
try{ <pd6,l\
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5j(3pV`_
output.writeInt(nStartPos.length); $V"NB`T
for(int i=0;i<nStartPos.length;i++) qX'w}nJ}H}
{ xl5n(~g)p
// output.writeLong(nPos); $YDZtS&h
output.writeLong(fileSplitterFetch.nStartPos); 7mulNq
output.writeLong(fileSplitterFetch.nEndPos); S@suPkQ<>
} nJ/wtw
output.close(); F?j;3@z[A
} 4m++>q
catch(IOException e){e.printStackTrace ();} ^+Ez[S{8
catch(Exception e){e.printStackTrace ();} ejj|l
} >:l;W4j
"cerg?ix
j7;v'eA`;7
//读取保存的下载信息（文件指针位置） Ks&~VU
private void read_nPos() f.Y9gkt3d
{ T-7'#uB.m
try{ 3Rid1;L0U
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); OHnHSb'?\
int nCount = input.readInt(); $cO"1mu
nStartPos = new long[nCount]; aubmA0w
nEndPos = new long[nCount]; <}pwFl8C)
for(int i=0;i<nStartPos.length;i++) k*bfq?E a
{ G~ZDXQ>5CP
nStartPos = input.readLong(); 7I;Give{
nEndPos = input.readLong(); 66\0JsT?3
} ld1t1'I'
input.close(); {8M=[4_`l
} 7e&R6j
catch(IOException e){e.printStackTrace ();} Oq{&hH/'}
catch(Exception e){e.printStackTrace ();} *[*E|by
} dfB#+wh
T:0X-U
2G"mm(
private void processErrorCode(int nErrorCode) gnbs^K w
{ .vRLK
System.err.println("Error Code : " + nErrorCode); &J|3uY,'j
} Kq/W-VyGh
mwFI89J'
_>HXQ6Hw
//停止文件下载 UTQ$sg|7p
public void siteStop() ~p~8T
{ +3e(psdg
bStop = true; ]B>Y +
for(int i=0;i<nStartPos.length;i++) b?-%Uzp<
fileSplitterFetch.splitterStop(); 5YIiO7@4
ogv86d
J'.:l}g!1
} ]s jFj
} /U<-N'|
//负责部分文件的抓取 uF>I0J#z?
**FileSplitterFetch.java <\x/Y$jm0n
*/ R!xs;|]
package NetFox; dQ^>,(
HZ=Dd4!
q`09
import java.io.*; zMX7 #,
import java.net.*; ~\hA-l36
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public class FileSplitterFetch extends Thread { iR4CY-
zdn e2
3y>.1
String sURL; //File URL s)yEVh
long nStartPos; //File Snippet Start Position V_U$JKJ1=
long nEndPos; //File Snippet End Position Rs)tf|`/
int nThreadID; //Thread's ID D@qq=M
boolean bDownOver = false; //Downing is over v:CYf_
boolean bStop = false; //Stop identical fl~k')s
FileAccessI fileAccessI = null; //File Access interface C 0*k@kGy
%Ua*}C
J),7ukLu^
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException g=pz&cz;>\
{ N;D(_:^
this.sURL = sURL; mT@UQCG
this.nStartPos = nStart; <(d^2-0
this.nEndPos = nEnd; :RHNV
nThreadID = id; }*$-rieg
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [?W3XUJ,Y
} .x6*9z#q
*P:`{ZV7=W
1SkGG0 W
public void run() DcoTa-~
{ 9`.b
while(nStartPos < nEndPos && !bStop) s;}';#
{ {exF"ap
mMrvr9%
:<ujk
try{ jb)z[!FbM
URL url = new URL(sURL); wx(|$2{h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9|jIrS%/~
httpConnection.setRequestProperty("User-Agent","NetFox"); UOF5&>MLb
String sProperty = "bytes="+nStartPos+"-"; Sijwh1j*V
httpConnection.setRequestProperty("RANGE",sProperty); (5-"5<-@R
Utility.log(sProperty); ,k{{ZP P
{FQ dDIj#
H|F>BjXn5
InputStream input = httpConnection.getInputStream(); B_`A[0H
//logResponseHead(httpConnection); k4pvp5}%
+?MjY[8j
]lQhIf6)k
byte[] b = new byte[1024]; 3KB)\nF#%
int nRead; }'kk}2ej`
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) L4.yrA-]C%
{ jc;&g)Rv
nStartPos += fileAccessI.write(b,0,nRead); j@UW[,UI
//if(nThreadID == 1) `Up<;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9jaYmY]~
} `{F8#
z(1h^.
CNbrXN
Utility.log("Thread " + nThreadID + " is over!"); J;m[1Mae&
bDownOver = true; 6xnJyEQUM
//nPos = fileAccessI.write (b,0,nRead); M P0ww$(
} K+T`'J4
catch(Exception e){e.printStackTrace ();} O|7q,bEm^
} Vize0fsD
} uT]_pKm
5?9}^s4
Vl^jTX5N
//打印回应的头信息 5I T'u3V
public void logResponseHead(HttpURLConnection con) BHZGQm
{ s}|IRDpp
for(int i=1;;i++) *i5&x/ds
{ P|HY=RMa
String header=con.getHeaderFieldKey(i); h]@Xucc
if(header!=null) @!%<JZEz3
//responseHeaders.put(header,httpConnection.getHeaderField(header)); e yTYg
Utility.log(header+" : "+con.getHeaderField(header)); Gjy'30IF
else Duptles
break; vU{ZB^+&6o
} 2Y 6/,W
} ,vg8iRa
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wZfR>|f
public void splitterStop() &lI.N~Ao
{ n)`*{uv$
bStop = true; ~Gwn||g78
} gvA&F|4
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(CZRX9TT1
} lzS"NHs<g(
kf"cd1
Vx* =
/* cO(|>&tJ
**FileAccess.java J=4S\0Z*
*//文件访问(定位，写) f+<-Jc
package NetFox; 1RRvNZW
import java.io.*; [>"qOFCr#:
#B+2qD>E
OY"{XnPZ
public class FileAccessI implements Serializable{ X*S|aNaLWW
C8&)-v|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @ULr)&9
RandomAccessFile oSavedFile; |":^3
long nPos; b.Y[:R_9&
=9pFb!KX
;PS[VdV
public FileAccessI() throws IOException *vBcT.|,
{ |_O; U=2
this("",0); i"w$D{N
} ?`FI!3j
NRoi` IIj
{'d?vm!r
public FileAccessI(String sName,long nPos) throws IOException deeOtco$LT
{ EO'3;mo,
oSavedFile = new RandomAccessFile(sName,"rw"); xZ,g6s2o
this.nPos = nPos; A|y&\~<A
oSavedFile.seek(nPos); TC R(
} H.i_,ZF
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{Lq uOC1
public synchronized int write(byte[] b,int nStart,int nLen) bd)A6a\h
{ sBRw#xyS
int n = -1; ,HMB`vF
try{ 4qyL' \d[
oSavedFile.write(b,nStart,nLen); @9vz%1B<l
n = nLen; ej!C^
} 1Ete;r%5=
catch(IOException e) Pi+,y
{ U4LOe}Ny
e.printStackTrace (); aNXu"US+Sp
} %X[|7D-
_Dk;U*2
zD)2af
return n; b,318R8+G
} 6"A|)fz
?"sk"{
dnNc,l&g
} E}1[&
5jYRIvM[Q~
Ah)7A|0rT
/* WfO6Fvx%
**SiteInfoBean.java ~@sx}u
*/ +Do7rl
package NetFox; ze#LX4b I
<[a9"G7
&p4q# p7,
public class SiteInfoBean { z),l&7
!vett4C* K
-{L[Wt{1
private String sSiteURL; //Site's URL GD*6tk;5/
private String sFilePath; //Saved File's Path "&C'K
private String sFileName; //Saved File's Name 4H1s"mP<
private int nSplitter; //Count of Splited Downloading File b(~NqV!i
u4.-AY {
%C)U F
public SiteInfoBean() KgKV(q=
{//nSplitter的缺省值为5 o'D6lkf0
//default value of nSplitter is 5 0V`/oaW;
this("","","",5); TH6g:YP`7
} KUuwScb\
NrL%]dl3/
a(BC(^1!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) S)Ld^0w
{ \h #vL
sSiteURL= sURL; KWN&nP +
sFilePath = sPath; l"ih+%S
sFileName = sName; tnKzg21%
this.nSplitter = nSpiltter; OwDjUKeN
!_V*VD
+o_`k!
} !-\*rdE{9
[0IeEjL
i-&kUG_X
public String getSSiteURL() Ye(0'*-jyc
{ %A64 Y<K
return sSiteURL; e#W@ep|n
} ikm4Y`c
]`:Fj|>
@rVmr{UE
public void setSSiteURL(String value) $wX5`d1
{ ^s24f?3
sSiteURL = value; l}<s~ip
} 9prG@
F /t;y\)
o*dhks[
public String getSFilePath() fT'A{&h|U
{ #UGbSOoCtn
return sFilePath; oA42?I ^
} 8SKDL[rN
w@oq.K
VDQ&BmJE
public void setSFilePath(String value) LU%g>?m.]
{ `D GO~RMp9
sFilePath = value; %*r Pd>*
} Vuz!~kLYIn
8K1+ttjm
ZY][LU~l8
public String getSFileName() Vxk0oIk`
{ My5X%)T>P
return sFileName; B;rq{ac!P]
} (1TYJ. Z
^&Qaf:M
{O!fV<Vx 9
public void setSFileName(String value) Cf%)W:Q9
{ L(X:=) !K0
sFileName = value; s!UC{)g,
} dn5T7a~
9Uk9TG5
V#sANi?mpo
public int getNSplitter() +/UInAM
{ Ya,>E@oc
return nSplitter; \W$>EH
} qP]Gl--q{
ozGK -$
VT0I1KQx.
public void setNSplitter(int nCount) xi|iV1A
{ E%$FX'8&
nSplitter = nCount; LTJ|EXYA
} l?#([(WM
} i2swots
h3JIiwv0!
eJ?SLMLY
/* 9]kWM]B)o
**Utility.java )DoY*'Cl
*/ /j.V0%
package NetFox; ?{^T&<18t
."=Bx2
BfhOe~+i
public class Utility { m4kmJaM
_u.l|yR
cL`l1:j\}
public Utility() ;,9|;)U?u
{ 0WYVt"|;}c
_YbHnb
hQX|wWh
} /~AajLxu3W
@3b0hi4
//线程睡眠 m~X:KwK4
public static void sleep(int nSecond) WXGLo;+>I
{ eaCEZHr$
try{ hp[8.Z$7
Thread.sleep(nSecond); Aja'`Mu
} k.0$~juu
catch(Exception e) |n* I}w^
{ o>j3<#?
e.printStackTrace (); I,q3J1K
} -+c_TJ.dC
} -vhgBru
>5XE*9
//日志 Xf$,ra"
public static void log(String sMsg) kbOo;<X9A
{ VE{t]>*-u
System.err.println(sMsg); \t )Zk2
} ;l~gA|A
w'cZ\<N[
|%TH|?kB
public static void log(int sMsg) H%sbf& gi
{ &o)j@5Y?
System.err.println(sMsg); {AQ3y,sh
} _L&C4 <e'
} :@kSDy+*Q
XB^z' P{-Y
-S9$C*t
/* xNl_Q8Z?R^
**TestMethod.java UJlKw `4
*/ %hOe `2#$
package NetFox; 6kYn5:BhIi
Vx?a&{3]-
`ZNzDr
public class TestMethod { M-0BQs`N
v')T^b F@
}JvyjE
public TestMethod() ?2DYz"/')
{ ///xx/weblogic60b2_win.exe }0qgvw
try{ b+3{ bE
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); T2^@x9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); lZE x0
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6Pd;I,k
fileFetch.start(); Fe`$mtPu.
} Ns&SZO
catch(Exception e){e.printStackTrace ();} "4i(5|whp?
S,qsCnz
C\ 9eR
} uiO8F*,!&r
qfG`H#cA<
XCQ=`3f
public static void main(String[] args) LLV:E{`p
{ <C]s\"o-`
new TestMethod(); :8\z 0
} i!sKL%z}
} 7e>n{rl
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