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)); MAR'y8I
} Gx/Oi)&/
for(int i=0;i<nEndPos.length-1;i++) >y7?-*0
{ ~,Zc%s~|
nEndPos = nStartPos[i+1]; >1Ibc=}g
} E<Y$>uKA
nEndPos[nEndPos.length-1] = nFileLength; GR_-9}jQP
} `4J$Et%S
} K\Wkoi5
iOghb*aW
Rr]Hy^w
//启动子线程 tXs\R(?T
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Se}c[|8
for(int i=0;i<nStartPos.length;i++) zY{A'<\O
{ 194)QeoFw
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ydA8wL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), A}9`S6@@
nStartPos,nEndPos,i); v@L;x [Q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K($Npuu]
fileSplitterFetch.start(); r#p9x[f<Y
} aeJHMHFc
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), YK'<NE3 4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); z>Y-fN`,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .|70;
nEndPos = " + nFileLength); |0b`fOS
// fileSplitterFetch[nPos.length-1].start(); i[3'ec3
kgP0x-Ap
aB&&YlR=n<
//等待子线程结束 f}P3O3Yv&
//int count = 0; !*N@ZL&X
//是否结束while循环 4Z&lYLq;
boolean breakWhile = false; G5 WVr$
O<?R)NH-P
14yv$,
while(!bStop) ^6V[=!& H
{ "ze|W\Bv!
write_nPos(); &j"?\f?
Utility.sleep(500); g}cq K
breakWhile = true; oD.Cs'
#q=Efn'
+a+Om73B2
for(int i=0;i<nStartPos.length;i++) ^hM4j{|&M
{ *.t7G
if(!fileSplitterFetch.bDownOver) Zb>?8
{ <\^8fn
breakWhile = false; }Zn}
break; aX'*pK/-
} sDlO#
} aEeodA<(
if(breakWhile) Z@!+v19^
break; mz0X3
hRhe& ,v
YNF k
//count++; <PH#[dH
//if(count>4) htF] W|z
// siteStop(); `M8i92V\qY
} ^u ~Q/4
"+G8d'%YV
9WyhZoPD*
System.err.println("文件下载结束！"); W^l-Y%a/o
} &Ok):`
catch(Exception e){e.printStackTrace ();} oap4rHk}
} `d}2O%P
S.NPZ39}ZE
2c*GuF9(0
//获得文件长度 x s|FE3:a
public long getFileSize() `X&gE,Ii
{ +cN8Y}V
int nFileLength = -1; .aQ \jA
try{ (O3nL.
URL url = new URL(siteInfoBean.getSSiteURL()); 2P0*NQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F={a;Dvrn
httpConnection.setRequestProperty("User-Agent","NetFox"); @\#td5'
/PIcqg
}o`76rDN
int responseCode=httpConnection.getResponseCode(); (f"4,b^]
if(responseCode>=400) yY q,*<G
{ [{,1=AB
processErrorCode(responseCode); SO!8Di
return -2; //-2 represent access is error 2BwO!Y[
} SwMc pNo
|CRn c:
*$g-:ILRuZ
String sHeader; vr=#3>
+CNv l
X'iWJ8
for(int i=1;;i++) wFZP,fQ9l
{ &tj!*k'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4.t-i5
//Utility.log(in.readLine()); ^ [@,
sHeader=httpConnection.getHeaderFieldKey(i); /%^#8<=|U
if(sHeader!=null) ew4U)2J+
{ N~'c_l
if(sHeader.equals("Content-Length")) >z@0.pN]7
{ c\j/k[\<
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); PEZ!n.'S
break; =UWI9M*sz
} WH^%:4
} =t?F6)Q
else EADqC>
break; w``U=sfmV
} {)sdiE
} _H@DLhH|=
catch(IOException e){e.printStackTrace ();} .7X^YKR
catch(Exception e){e.printStackTrace ();} sFRQe]zCcP
u>vL/nI
X^jfuA
Utility.log(nFileLength); r9?Mw06Wc5
qJ-/7-$ ^
G18b$z
return nFileLength; TB31- ()
} ^U/O!GK
ZbKg~jdF
`Urhy#LC
//保存下载信息（文件指针位置） $[ *w"iQ
private void write_nPos() ,I;>aE<#
{ ;!Fn1|)
try{ ,eS)e+yzc2
output = new DataOutputStream(new FileOutputStream(tmpFile)); k+*u/neh
output.writeInt(nStartPos.length); x]j W<A
for(int i=0;i<nStartPos.length;i++) %8v\FS
{ xyXa .
// output.writeLong(nPos); 4^<?Wq~
output.writeLong(fileSplitterFetch.nStartPos); n+M<\
output.writeLong(fileSplitterFetch.nEndPos); ]6j{@z?{
} C;yZ
output.close(); #GFr`o0$^
} @2i9n
catch(IOException e){e.printStackTrace ();} <:CkgR$/{
catch(Exception e){e.printStackTrace ();} ))Za&S*<
} 'V>-QD%1
M"L=L5OH-
RxQ*
//读取保存的下载信息（文件指针位置） E"IZ6)Q
private void read_nPos() Dw"\/p:-3
{ 7zj{wp!
try{ nO-#Q=H,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 'Pbr v
int nCount = input.readInt(); rPm x
nStartPos = new long[nCount]; yB!dp;gM{
nEndPos = new long[nCount]; ?e?!3Bx;EM
for(int i=0;i<nStartPos.length;i++) t_1LL >R
{ /x *3}oI
nStartPos = input.readLong(); 3XNCAb2
nEndPos = input.readLong(); DHRlWQox
} * v#o
input.close(); rvM{M/4
} nJ;.Td
catch(IOException e){e.printStackTrace ();} .6J$,.Ig
catch(Exception e){e.printStackTrace ();} cWm$;`Q#\
} # f\rt
8zb/xP>
n=q76W\
private void processErrorCode(int nErrorCode) 0n'_{\yz
{ G#$-1"!`
System.err.println("Error Code : " + nErrorCode); _yT Ed"$
} -G=]=f/'
fV~[;e;U.
vih9KBT
//停止文件下载 J[kTlHMD
public void siteStop() Dt1jW
{ 4I[P>
bStop = true; B<C&xDRZ0
for(int i=0;i<nStartPos.length;i++) \{D" !e
fileSplitterFetch.splitterStop(); bI`g|v
),!qTjD
6S{l'!s'
} )U#K
} ugBCBr
//负责部分文件的抓取 _"{Xi2@H
**FileSplitterFetch.java HVAYPerH
*/ {4PwLCy
package NetFox; 9tnD=A<PS
!n%j)`0M
nr3==21Om4
import java.io.*; `GLx#=Q
import java.net.*; 1.>m@Slr>
HbIF^LeY|R
lLIAw$
public class FileSplitterFetch extends Thread { @}ZVtrz
1 TXioDs=_
"Y.y:Vv;
String sURL; //File URL p K$`$H
long nStartPos; //File Snippet Start Position R|Q?KCI&
long nEndPos; //File Snippet End Position 8?C5L8)
int nThreadID; //Thread's ID 47B&s
boolean bDownOver = false; //Downing is over 5-A\9UC*@
boolean bStop = false; //Stop identical &nK<:^n
FileAccessI fileAccessI = null; //File Access interface ./~(7o$
y_[vr:s5pG
I`#JwMU;m
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException S|}L&A
{ AOx[
this.sURL = sURL; i-&yH
this.nStartPos = nStart; t`QENXA}
this.nEndPos = nEnd; Bbp|!+KP{(
nThreadID = id; q cno^8R
fileAccessI = new FileAccessI(sName,nStartPos);//定位 LH6vLuf
} LIrb6g&xj_
wKHBAW[i]
`F6C-
public void run() tf G@&&%9
{ fc@A0Hf
while(nStartPos < nEndPos && !bStop) &m vSiyKX
{ 048kPXm`
DV{=n C
M^I(OuRMeI
try{ hv+zGID7
URL url = new URL(sURL); PI<vxjOK`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [/ZO q
httpConnection.setRequestProperty("User-Agent","NetFox"); :hA#m[
String sProperty = "bytes="+nStartPos+"-"; ~)'k 9?0
httpConnection.setRequestProperty("RANGE",sProperty); Q@HV- (A
Utility.log(sProperty); Y\tui+?J
c`Wa^(
tnIX:6
InputStream input = httpConnection.getInputStream(); u=yOu^={
//logResponseHead(httpConnection); |cY`x(?yP
GKCroyor
9!tW.pK5
byte[] b = new byte[1024]; \j.:3Xr
int nRead; @ .KGfNu
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) FPTK`Gd0
{ ?%kV?eu'
nStartPos += fileAccessI.write(b,0,nRead); 8XbT`y
//if(nThreadID == 1) S[QrS7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I2DpRMy
} J8~haim
9>$p
-Qe Z#w|
Utility.log("Thread " + nThreadID + " is over!"); A\;U3Zu
bDownOver = true; Wez5N
//nPos = fileAccessI.write (b,0,nRead); O'~+_ykTl
} hzC>~Ub5
catch(Exception e){e.printStackTrace ();} U;I9 bK8
} Aa]"
} t:c.LFrF
-.3w^D"l
@|)Z"m7
//打印回应的头信息 L8n|m!MOD
public void logResponseHead(HttpURLConnection con) y_9Ds>p!T
{ 6zn5UW#q
for(int i=1;;i++) 5:Uso{
{ Qci]i)s$js
String header=con.getHeaderFieldKey(i); -{_PuJ "
if(header!=null) bjS{(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3mni>*q7d
Utility.log(header+" : "+con.getHeaderField(header)); Sx\]!B@DSu
else 59-c<I/}f
break; ,2)6s\]/b
} lys#G:H]
} &~w}_Fjk
BluVmM3Vj
9{uO1O\
public void splitterStop() P }uOJVQ_
{ $wU\Js`/S]
bStop = true; u2[w#
} A(0lM`X
{y;n:^
4`R(?
} _tXlF;
%%wNZ{
M@ZI\
/* 9g?(BI^z
**FileAccess.java s9d_GhT%-
*//文件访问(定位，写) ]9,;K;1<
package NetFox; FGQzoS
import java.io.*; v9UD%@tZ
#o2[hibq
D,ln)["xm
public class FileAccessI implements Serializable{ C8\^#5
TOAAQ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 JMM W
RandomAccessFile oSavedFile; bYPKh
long nPos; 'Z|mQZN
ctJE+1#PH
<^uBoKB/f
public FileAccessI() throws IOException <d_!mKw
{ @OHm#`~
this("",0); ]$_NyAoBb
} 2 Vrw
!v0LBe4
ofv)SCjd
public FileAccessI(String sName,long nPos) throws IOException alvrh'51
{ K96<M);:g
oSavedFile = new RandomAccessFile(sName,"rw"); +?!(G}5
this.nPos = nPos; *D3/@S$B
oSavedFile.seek(nPos); ?K\axf>F
} mdgi5v
#lW`{i
U`m54f@U
public synchronized int write(byte[] b,int nStart,int nLen) E\,-XH
{ z]9MM 2+
int n = -1; k)Qtfj}uij
try{ :[!j?)%>
oSavedFile.write(b,nStart,nLen); `$C n~dT
n = nLen; j,dR,Nd
} \} :PLCKT
catch(IOException e) Q)[C?obd v
{ <3hRyG@vB
e.printStackTrace (); H+Sz=tg5
} 7x4PaX(
,Vk3kmuvr]
NPe%F+X
return n; s}% M4
} %F4%H|G
H}bJ"(9$vC
OH(waKq2I
} =rCIumqD-}
V% 6I\G2/:
r? E)obE
/* }@+:\
**SiteInfoBean.java "5wa91*
*/ ^RtIh-Z.9
package NetFox; c|@bwat4
lv+TD!b
hNmJ!Uo
public class SiteInfoBean { (c &mCJN
8C9-_Ng`
DX K?Cv71z
private String sSiteURL; //Site's URL <;Zmjeb+#
private String sFilePath; //Saved File's Path cP_.&!T
private String sFileName; //Saved File's Name JHTSUq
private int nSplitter; //Count of Splited Downloading File o="M
zv,jM0-
l3I:Q^x@
public SiteInfoBean() o!ebs0
{//nSplitter的缺省值为5 pohp&Tcm
//default value of nSplitter is 5 @8r pD"x
this("","","",5); S2VA{9:m
} D!-g&HBTC
V/I<g
F%D.zvKN
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]*[ 2$
{ *]/zc1Q4M
sSiteURL= sURL; wHMX=N1/
sFilePath = sPath; CD( :jM?
sFileName = sName; iN8zo:&Z
this.nSplitter = nSpiltter; lBvR+9Qw
xH"/1g
8(&[Rs?K
} UIN<2F_
]{mPh\
>rKIG~P_
public String getSSiteURL() !0LWa"
{ My[pr_xg
return sSiteURL; ;LSANr&
} MPg)=LI
c>:wd@w
ywm8N%]v
public void setSSiteURL(String value) tm RXgTS
{ k],Q9
sSiteURL = value; !1H# 6
} 9BBmw(M}
0e ~JMUb
a:IC)]j$_
public String getSFilePath() EF}\brD1
{ nIy}#MUd|q
return sFilePath; Y}|X|!0x
} vJc-6EO
'RYIW/a
`1{ZqRFQ
public void setSFilePath(String value) MSqVlj
{ /,&<6c-Q@W
sFilePath = value; O#~yKqB
} /quc}"__
`yXg{lk
O6a<`]F
public String getSFileName() P& -Qc
{ })8N5C+KU
return sFileName; `WFw3TI
} f:|1_j
6J6BF%
.A{tQ1&_
public void setSFileName(String value) QIvVcfM^
{ ^"1n4im
sFileName = value; ~{B7 k:
} ju8q?Nyhs
|5~#&v_
j94=hJVKi
public int getNSplitter() ;jvBF4Lb>
{ l2rd9-T
return nSplitter; #;qdY[v
} lN?qp'%H`
lC("y' ::
#+HJA42
public void setNSplitter(int nCount) `nv~NLkl
{ " H&W}N
nSplitter = nCount; #crQ1p) \
} 5Y'qaIFR
} ~f1%8z
lVR~Bh
_j/<{vSy
/* #TX/aKr:
**Utility.java E+R1 !.
*/ )Y6 +
package NetFox; i6tf2oqO7
o_Z5@F
K&ZtRRDd
public class Utility { .4M.y:F
so)[59M7
&5spTMw8
public Utility() ZQoU3AD;
{ AJ?r,!)
wh\}d4gN
2"kLdD
} YY((V@|K
7BjJhs
//线程睡眠 (Hz^)5(~
public static void sleep(int nSecond) ZaDyg"Tw+
{ )oDHeU<&
try{ zRl3KjET
Thread.sleep(nSecond); :W:K:lk
} lhz{1P]s
catch(Exception e) qL&[K>2z
{ }Jve cRtg1
e.printStackTrace (); W*4-.*U8a
} ox>^>wR*
} O=&0H|B
m!4ndO;0vh
//日志 Ins`l
public static void log(String sMsg) uK#4(eY=W
{ dTC7Fm
System.err.println(sMsg); ~xfP:[u
} 7he,?T)vD
T`.O'!
Lh"<XYY
public static void log(int sMsg) ?WUA`/[z
{ HU}7zK2
System.err.println(sMsg); _ Yx]_Y9I
} YTX,cj#D^&
} i]y<|W)Q3
`*["UER
k\YG^I
/* a|x.C6Pe
**TestMethod.java axRV:w;E<
*/ [b<oDX#
package NetFox; |zNX=mAV
u\x}8pn
='sHj4hU
public class TestMethod { *@r/5pM2}
}bpQq6ZF
+L|?~p`V
public TestMethod() /y#f3r+*2
{ ///xx/weblogic60b2_win.exe [f-?ymmT
try{ mpEK (p
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0r] t`{H
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }6}l7x
SiteFileFetch fileFetch = new SiteFileFetch(bean); E7Ul;d
fileFetch.start(); 3cyHfpx-W
} p8H'{f\G
catch(Exception e){e.printStackTrace ();} .fFCC`&T
A*R^n}sh
ZW8vza
} y8Z_Itlf
5 +YH.4R
]^n7
public static void main(String[] args) N1S{suic
{ R'`qKc
new TestMethod(); "f2$w
} m 3hrb-
} 2K6qY)/_
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