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)); Nr*X1lJ6
} w?8\9\ ;?
for(int i=0;i<nEndPos.length-1;i++) A1Uy|Dl
{ ] `q]n
nEndPos = nStartPos[i+1]; kMLJa=]$
} tEo-Mj5:
nEndPos[nEndPos.length-1] = nFileLength; NMhpKno
} rx9y^E5T`;
} ?>V>6cDQ
T fIOS]
[Pjitw/?
//启动子线程 v#s*I/kw
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; z6B#F<h
for(int i=0;i<nStartPos.length;i++) W)T'?b'.
{ b]xoXC6@t
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S!gzmkGcj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #M'V%^xP
nStartPos,nEndPos,i); zv;xxAX
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [N9yWuc
fileSplitterFetch.start(); 0&CXR=U5
} [kxOv7a
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [~\]<;;\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); IqepR >5t
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", PXtF#,roP
nEndPos = " + nFileLength); 3XDU(#
// fileSplitterFetch[nPos.length-1].start(); }hg2}g99
v)gMNzt
@K*W3&TO
//等待子线程结束 B@dCCKc%/
//int count = 0; ^"=G=* /
//是否结束while循环 *ej< 0I{
boolean breakWhile = false; KDGrX[L:6
+|X`cmnuU
J}8p}8eF,
while(!bStop) O(=9&PRi
{ ]&D=*:c
write_nPos(); -Edy ~;_
Utility.sleep(500); |nLq4.
breakWhile = true; p"jze3mF
i_r708ep6
jpZq]E9`P
for(int i=0;i<nStartPos.length;i++) ' i5KRFy-
{ u=]*,,5<
if(!fileSplitterFetch.bDownOver) yk5K8D[tV
{ < Mu`,Kv*
breakWhile = false; +%K~
break; vV9vB3K5?
} _&s pMf
} 8qw{e`c
if(breakWhile) &?1^/]'"r
break; 4J(-~
Q/4ICgo4
&)||~
//count++; cqs.[0 z#B
//if(count>4) 7 wEv`5
// siteStop(); puWMgvv
} TKGaGMx6@
'yA/sZ
V'Kied+
System.err.println("文件下载结束！"); ;]>)6
} 8c9<kGm$E
catch(Exception e){e.printStackTrace ();} aL90:,V
} M,li\)J!&
f`/('}t
b30Jr2[
//获得文件长度 !'BXc%`x[
public long getFileSize() O j:I @c
{ X9FO"(J
int nFileLength = -1; tH *|
try{ vbtZ5Gm
URL url = new URL(siteInfoBean.getSSiteURL()); S|LY U!IWZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $^?VyHXvY
httpConnection.setRequestProperty("User-Agent","NetFox"); p19@to5l
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1>L'F8"
int responseCode=httpConnection.getResponseCode(); fvi0gE@bd
if(responseCode>=400) 6\K\d_x
{ Y[}A4`
processErrorCode(responseCode); * O?Yp%5NH
return -2; //-2 represent access is error Q#qfuwz
} u'_}4qhCC;
}Kp<w,
GQA\JYw|oY
String sHeader; rrj.]^E_~
m}RZ)c
3Os0<1@H
for(int i=1;;i++) t[X^4bZd
{ \**j\m
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !yrh50tD
//Utility.log(in.readLine()); iZeq l1O
sHeader=httpConnection.getHeaderFieldKey(i); W,CAg7:*
if(sHeader!=null) ' F9gp!s8~
{ &<uLr *+*
if(sHeader.equals("Content-Length")) +YW;63"o
{ `#`jU"T|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); X~"p]V_
break; `G`R|B
} leH7II9
} VR&dy|5BO
else &V<f;PF(I
break; 3rMJC\h
} Kn@#5MC rU
} 2=8PA/
catch(IOException e){e.printStackTrace ();} H2#o X
catch(Exception e){e.printStackTrace ();} 9Scg:}Nj
KZZY9
lA/-fUA
Utility.log(nFileLength); vBF9!6X.
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M_ %-A
return nFileLength; ug ;Xoh5w
} "P(obk
$rr@3H+
m26YAcip}
//保存下载信息（文件指针位置） ?(d1;/0v>
private void write_nPos() N AY3.e
{ mS![J69(
try{ {xov8M
output = new DataOutputStream(new FileOutputStream(tmpFile)); #m?)XB^_
output.writeInt(nStartPos.length); 5toa@#Bc%
for(int i=0;i<nStartPos.length;i++) AL3iNkEa
{ t;h`nH[
// output.writeLong(nPos); z5M6
output.writeLong(fileSplitterFetch.nStartPos); {en'8kS
output.writeLong(fileSplitterFetch.nEndPos); HSROgBNI:
} HNBmq>XDc
output.close(); vFntzN>#
} a oU"
catch(IOException e){e.printStackTrace ();} W~D_+[P|_
catch(Exception e){e.printStackTrace ();} Q]N&^ E
} =|IlORf<
E/%"%&`8j
w@cW`PlF
//读取保存的下载信息（文件指针位置） C]5 kQ1Og
private void read_nPos() .yXqa"p
{ g:JSy
try{ '&#gs P9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); SKnYeT
int nCount = input.readInt(); JRFUNy1+e1
nStartPos = new long[nCount]; ws!~MSIy
nEndPos = new long[nCount]; +8N6tw/&
for(int i=0;i<nStartPos.length;i++) !^su=c
{ =VuSi(d;e{
nStartPos = input.readLong(); At=d//5FFP
nEndPos = input.readLong(); H#;*kc a4
} C,l,fT
input.close(); =tt3nfZ9
} hd9HM5{p
catch(IOException e){e.printStackTrace ();} ztSQrDbbb4
catch(Exception e){e.printStackTrace ();} (M$>*O3SR
} HV/:OCK
^OWG9`p+
=r ^_D=
private void processErrorCode(int nErrorCode) |R@T`dW
{ o68i0aFW
System.err.println("Error Code : " + nErrorCode); T pF[-fO
} EC,`t*<
MU a[}?
w($a'&d`0
//停止文件下载 TMPk)N1Ka
public void siteStop() <Jhd%O
{ YFB>GQ;
bStop = true; }5oI` 9VT
for(int i=0;i<nStartPos.length;i++) V)/J2-w
fileSplitterFetch.splitterStop(); ,/b!Xm:
0@cIj ]
pIcg+~
} T*C25l;w
} 4y7_P0}:B
//负责部分文件的抓取 7mMGH(
**FileSplitterFetch.java "*t6KXVaM
*/ a,RCK~GR
package NetFox; A[;deHg=
MYy58N
vQi=13Pw
import java.io.*; PZ8,E{V
import java.net.*; 5<ruN11G
k B]`py!
Y#68_%[
public class FileSplitterFetch extends Thread { ?cRF;!o"
/ie&uWy
Ei@
String sURL; //File URL \/3(>g?4
long nStartPos; //File Snippet Start Position 0x-g0]
long nEndPos; //File Snippet End Position [%dsq`b#
int nThreadID; //Thread's ID fS4W*P[B3
boolean bDownOver = false; //Downing is over ktTP~7UVi
boolean bStop = false; //Stop identical aHW34e@ebL
FileAccessI fileAccessI = null; //File Access interface \~,\|
e3;D1@
\Yr*x7!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException d%'#-w'
{ |@JTSz*Or
this.sURL = sURL; x0Loid\f
this.nStartPos = nStart; lF!PiL
this.nEndPos = nEnd; vNs%e/~vj
nThreadID = id; "V]*ov&[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 z fSE7i0
} mk1R~4v
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l6HtZ(
public void run() ekyCZ8iai
{ 4};@QFT*
while(nStartPos < nEndPos && !bStop) (cLKhn@
{ &]n }fq
t(*n[7e
6Oy:5Ps8a
try{ (X"5x]7]
URL url = new URL(sURL); P knOeW"j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =figat
httpConnection.setRequestProperty("User-Agent","NetFox"); G`0O5G:1
String sProperty = "bytes="+nStartPos+"-"; q\o#<'F1J
httpConnection.setRequestProperty("RANGE",sProperty); /OztkThx=
Utility.log(sProperty); iiq `:G
E72N=7v"
tz;o6,eb
InputStream input = httpConnection.getInputStream(); *Sj)9mp
//logResponseHead(httpConnection); u$%C`v>
:;eOhZ=_
kb2C9<
byte[] b = new byte[1024]; c%doNY9Q
int nRead; F-|DZ?)k5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) u9S*2'
{ 7w)8s
nStartPos += fileAccessI.write(b,0,nRead); jD S\
//if(nThreadID == 1) 2T2<I/")O
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G^)]FwTs
} x&;AY
2PSExK57
j "<?9/r
Utility.log("Thread " + nThreadID + " is over!"); L1RD`qXu.
bDownOver = true; WS n>P7sY
//nPos = fileAccessI.write (b,0,nRead); 1iz =i^}
} ^aAs=KditO
catch(Exception e){e.printStackTrace ();} {"Sv~L|J;
} \UK}B
} 5\quh2Q_
Ro2V-6/
PM84Z@Y
//打印回应的头信息 wL),/i&<
public void logResponseHead(HttpURLConnection con) nzaDO-2!
{ #VX]trh,
for(int i=1;;i++) wd*B3
{ jV*10kM<
String header=con.getHeaderFieldKey(i); 9y6u&!PZ\
if(header!=null) LD[\eJ_
//responseHeaders.put(header,httpConnection.getHeaderField(header)); GW>F:<p
Utility.log(header+" : "+con.getHeaderField(header)); &qXobJRM
else )b1hF
break; QHO n?e
} cN&Ebn
} -rcEG!
E6~VHQa2?
}~@/r5Zl
public void splitterStop() SzpUCr"
{ &{8:XJe*,%
bStop = true; a%`Yz"<lQ
} ^x O](,H
Y[7prjd
_@B?
} yy{YduI
fphCQO^#vW
KU$,{Sn6@
/* 3<XuJ1V&
**FileAccess.java "7%jv[
*//文件访问(定位，写) BT[|f[1
package NetFox; fu\j
import java.io.*; m@+v6&,
`"CA$Se8
o$L%t@
public class FileAccessI implements Serializable{ |E6_TZ#=
e: Sd#H!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 87!jn'A
RandomAccessFile oSavedFile; dnD@BQ
long nPos; >|%3j,<U
[6l0|Y
pl r@
public FileAccessI() throws IOException Gz{%Z$A~o
{ kB@gy}
this("",0); Lm}.+.O~d
} O)&W0`VY
AAa7)^R
ddN(L`nd
public FileAccessI(String sName,long nPos) throws IOException VCc=dME
{ ^9,^BHlC0
oSavedFile = new RandomAccessFile(sName,"rw"); =A,B'n\R
this.nPos = nPos; `G!HGzVx;j
oSavedFile.seek(nPos); 4$VDJ
} o A2oX
)e0kr46
P@UE.0NYX
public synchronized int write(byte[] b,int nStart,int nLen) "v?F4&\ 8
{ 0^>,
int n = -1; H}GGUE&c*
try{ &mtt,]6C_
oSavedFile.write(b,nStart,nLen); npzp/mcIe)
n = nLen; {?lndBP<
} z**2-4 z
catch(IOException e) (mP{A(kwJ
{ |1CX?8)b=
e.printStackTrace (); nyPeN?-
} rVP\F{Q4Tr
0e0)1;t\
H'#06zP>5
return n; AcuZ?LYzK
} ,(q] $eOZ
grE(8M
4#>Z.sf
} ?u:`?(\
L~/,;PHN
>(P(!^[f
/* lv/im/]v
**SiteInfoBean.java RYCiO,+
*/ j17h_ a;
package NetFox; `Ns@W?
=cV|o]
Z4Q]By:/L
public class SiteInfoBean { RgV3,z
bj@sci(1?
=$4I}2
private String sSiteURL; //Site's URL f@YdL6&d-
private String sFilePath; //Saved File's Path BhDg\oxZ
private String sFileName; //Saved File's Name A'`F Rx(
private int nSplitter; //Count of Splited Downloading File =| T^)J
mOj;0 R
.g}N@
public SiteInfoBean() BNJ0D
{//nSplitter的缺省值为5 Z:^#9D{
//default value of nSplitter is 5 M>5OC)E
this("","","",5); + Fo^NT
} eZa7brC|
V5$Gb6?K
P^"RH&ZQJ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) J|{50?S{^
{ t* Ct*
sSiteURL= sURL; )rP,+B?W
sFilePath = sPath; \azMF}mb
sFileName = sName; D)x^?!
this.nSplitter = nSpiltter; _fZec+oM
h(yFr/
hK)'dG*
} 3}s]F/e
L}{3_/t
"{vWdY|"
public String getSSiteURL() wG MhKZE
{ 7~+Fec`Ut*
return sSiteURL; mvH8hvD9
} ?3K~4-!?/
'V^M+ng
tf7HhOCYX
public void setSSiteURL(String value) Gn4b*Y&M]3
{ (N&i4O-I
sSiteURL = value; =YVxQj
} !HU$V9C
YK{J"Kof
'8zd]U
public String getSFilePath() 7+f6?
{ [err$
return sFilePath; R.WB.FP
} d #1&"(
>)C7IQ/
\:Tq0|]Px
public void setSFilePath(String value) 9d|8c > I
{ 8/j|=Q,5
sFilePath = value; R98YGW_ dT
} ^@8XJ[C,_
@~s5{4
dakHH@Q
public String getSFileName() ;UgwV/d
{ V H`_
return sFileName; ZKrK>X
} \?t8[N\_[(
@` Pn<_L
=(hBgNH
public void setSFileName(String value) mD7NQ2:wA
{ _4) t
sFileName = value; 8tSY|ME
} oQh;lb
r=3`Eb"t
FJH>P\+
public int getNSplitter() \EU3i;BNT%
{ ][l5S*CC_
return nSplitter; w^8Q~3|7
} |sr\SCx
9^g8VlQdT
r3?8nQ$
public void setNSplitter(int nCount) +|bmUm<2
{ `^{G`es
nSplitter = nCount; 5'f_~>1Wt
} !I1p`_(_7
} =7TWzUCO#
Trh t2Iv
(BtU\f#d
/* eCKm4l'BZ
**Utility.java Eh;Ia6}
*/ i_m&qy<v
package NetFox; V0m1>{
wuY-f4
:_i1gY)
public class Utility { xib}E[-l#
JdI*@b2k[
yn ofDGAf
public Utility() uY)4y0
{ U%r{{Q1
2X' H^t]7
gNxv.6Pp=
} z)KoK`\mE"
h(nE)j
//线程睡眠 s[{8:Px
public static void sleep(int nSecond) Ay6T*Nu`
{ 9nQyPb6
try{ VB |k
Thread.sleep(nSecond); Mz$qe
} $I-iq @
catch(Exception e) 3F;0a ;[
{ m`zd0IRTP
e.printStackTrace (); w7~]c,$y.
} chD7^&5]
} bny@AP(CY+
rkS'OC
//日志 +Q_xY>ej
public static void log(String sMsg) 0e"KdsA:<U
{ "Vc|D (g
System.err.println(sMsg); bZWR.</
} YdvXp/P:|
X)]>E]X
EhO\N\p(Q=
public static void log(int sMsg) pHVDug3
{ /oe0
System.err.println(sMsg); @.cord`
} 5[zr(FuE
} A<H]uQ>
nUONI+6Z/
S|u5RU8*"|
/* |af<2(d
**TestMethod.java ;QuxTmWp^
*/ 6k,@+@]t.
package NetFox; 0|va}m`<3G
nq7)0F%e
A|IPQ=
public class TestMethod { ~qb?#IY]`
D.AiqO<z
wMF1HT<*
public TestMethod() 056yhB
{ ///xx/weblogic60b2_win.exe n$j B"1
try{ >Gg[J=7`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); aAoAjVNkK
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); u(r T2
SiteFileFetch fileFetch = new SiteFileFetch(bean); "OUY^ cM
fileFetch.start(); Zq1> M'V;
} UBM8l
catch(Exception e){e.printStackTrace ();} .O~rAu*K
b,HXD~=
&C,]c#-+
} 3S^Qo9S
YA8/TFu<_
Tz&cm=
public static void main(String[] args) BI#(L={5
{ ?b^<Tny
new TestMethod(); 2 (ux
} )CL/%I,^
} cv_O2Q4,@
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