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)); E8iadf49
} Gp ^ owr
for(int i=0;i<nEndPos.length-1;i++) ;h-G3>Il
{ DtF![0w/
nEndPos = nStartPos[i+1]; =o{: -EKQF
} 0(9I\j5`TT
nEndPos[nEndPos.length-1] = nFileLength; e(n2+S#N
} RM^?&PM85
} or!D
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>OKS/(I0
//启动子线程 `!,\kc1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; BBU84s[
for(int i=0;i<nStartPos.length;i++) R5NRCI
{ 7<R6T9g
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C*{15!d:G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ##`;Eh0a
nStartPos,nEndPos,i); U/3e,`c
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nF. ;LM
fileSplitterFetch.start(); yo?g"vbE
} &Qtp"#{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f=_Bx2ub
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); UYcyk $da
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", dWW-tHv#
nEndPos = " + nFileLength); PK-}Ldj
// fileSplitterFetch[nPos.length-1].start(); )-Mn"1ia
do=x9k@Q
UPVO~hB;
//等待子线程结束 'TK$ndy;7}
//int count = 0; KM_)7?`
//是否结束while循环 []=FZ`4
boolean breakWhile = false; C NzSBm
cy&
(}*\ {
while(!bStop) F;?TR[4!k
{ AF*ni~
write_nPos(); Lt;.Nw
Utility.sleep(500); ~4=]%XYz
breakWhile = true; ,<;l"v(
K4?t' dd]
JO&;bT<
for(int i=0;i<nStartPos.length;i++) aR="5{en{:
{ uGP[l`f|FQ
if(!fileSplitterFetch.bDownOver) 9LqMQv"xW
{ Ypn%[sSOp
breakWhile = false; >tmnj/=&
break; S<y>Y
} F;d%@E_Bc
} .`p<hA)%[C
if(breakWhile) CzzUi]*Ac{
break; w| -0@
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//count++; ,`%k'ecN
//if(count>4) q19k<BqR
// siteStop(); `r~`N`o5A
} 8`AcS|k
9&[)(On74
fR]p+\#8u*
System.err.println("文件下载结束！"); E,*JPK-A x
} mc0sdb,c$
catch(Exception e){e.printStackTrace ();} 3ZW/$KP/
} nJldz;
[0%yJH
NSMjr_
//获得文件长度 @b::6n/u
public long getFileSize() OQytgXED
{ |aI|yq)
int nFileLength = -1; IL+#ynC
try{ 4DQ07w
URL url = new URL(siteInfoBean.getSSiteURL()); bK_0NrXP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9D{u,Q V
httpConnection.setRequestProperty("User-Agent","NetFox"); KA|&Q<<{@
g( ]b\rj
nR,Qm=;
int responseCode=httpConnection.getResponseCode(); u|_LR5S!j
if(responseCode>=400) kz7vbY
{ 2cs?("8e%
processErrorCode(responseCode); dJdD"xj
return -2; //-2 represent access is error ys&"r":I
} g^s+C Z
wq:b j=j
'|YtNhWZ?
String sHeader; K:>NGGY8r
L<f-Ed9|
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for(int i=1;;i++) ')AByD}Hi]
{ _%A/ )
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); '\ph`Run
//Utility.log(in.readLine()); -vv
sHeader=httpConnection.getHeaderFieldKey(i); $:%*gY4~76
if(sHeader!=null) iN:G/ss4O
{ T!m42EvIvE
if(sHeader.equals("Content-Length")) $\0cJCQ3
{ -{yDk$"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); DHh+%|e
break; SBCL1aM
} v?Z'[l
} i>ESEmb-
else k9*J*7l-m
break; ax-=n(
} ^;V}l?J_s
} QE7+rBa
catch(IOException e){e.printStackTrace ();} 0=N4O!X9
catch(Exception e){e.printStackTrace ();} vbr~<JT=
'P@=/
ucQezmie
Utility.log(nFileLength); G*)s%2c>h
zrLhQ3V#>
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return nFileLength; &GXtdO>;Zv
} pj!k|F9
W@:^aH
]h #WkcXQ
//保存下载信息（文件指针位置） GIl:3iB49
private void write_nPos() |RHO+J
{ H/cs_i
try{ EsT0"{
output = new DataOutputStream(new FileOutputStream(tmpFile)); ggrI>vaw
output.writeInt(nStartPos.length); jG+T.
for(int i=0;i<nStartPos.length;i++) R19'|TJ
{ qJ\X~5{
// output.writeLong(nPos); Z7`5x
output.writeLong(fileSplitterFetch.nStartPos); B*9
output.writeLong(fileSplitterFetch.nEndPos); fswZM\@
} Eem 2qKj
output.close(); Ix( 6
} i FC"!23f
catch(IOException e){e.printStackTrace ();} =^BqWC2~
catch(Exception e){e.printStackTrace ();} o8w-$ Qb
} Nawp t%
$@_YdZ!
l0gH(28K
//读取保存的下载信息（文件指针位置） 6tOP}X
private void read_nPos() "AT&!t[J
{ bZxv/\
try{ o:Ln._bj
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 4qqF v?O[r
int nCount = input.readInt(); a^@+%?X
nStartPos = new long[nCount]; y' 2<qj
nEndPos = new long[nCount]; I|$'Q$m~
for(int i=0;i<nStartPos.length;i++) =Ov9Kf
{ \V._Z>]
nStartPos = input.readLong(); 91BY]N
nEndPos = input.readLong(); BfX%|CWh
} 0Wa#lkn$I
input.close(); g;$E1U=R-E
} HkW/G[7x&
catch(IOException e){e.printStackTrace ();} lTn;3'
catch(Exception e){e.printStackTrace ();} 5fU!'ajaN7
} )URwIe{
g+:$X- r
#N; $
private void processErrorCode(int nErrorCode) cB{%u '
{ %rFP#L
System.err.println("Error Code : " + nErrorCode); .8-PB*vb
} )8:n}w
<inl{CX/
%wOOzp`
//停止文件下载 k"t>He
public void siteStop() C,[L/!
{ P~&O4['<
bStop = true; TLy;4R2Nn
for(int i=0;i<nStartPos.length;i++) &q.)2o#Q.
fileSplitterFetch.splitterStop(); O ,l\e3;
&u&2D$K,tp
}K?F7cD
} )sqaR^
} 8^i[j\Y;6
//负责部分文件的抓取 5@K\c6
**FileSplitterFetch.java bC6X?m=
*/ c qv.dC
package NetFox; L%f-L.9`u
,KT<4
6tX.(/+L
import java.io.*; QI.t&sCh5
import java.net.*; I`lDWL
[S%J*sz~
HP#ki!'
public class FileSplitterFetch extends Thread { 9_eS`,'
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0"hiCGm'
String sURL; //File URL Ec+22X
long nStartPos; //File Snippet Start Position ?.8<-
long nEndPos; //File Snippet End Position DQcWq'yY^
int nThreadID; //Thread's ID 0(\p<qq
boolean bDownOver = false; //Downing is over .hxin[Y
boolean bStop = false; //Stop identical q{/*n]K
FileAccessI fileAccessI = null; //File Access interface X+@s]
=<Hy"4+?.
ZHz^S)o\[s
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException B.El a
{ FZeP<Ban
this.sURL = sURL; U8E0~[y'
this.nStartPos = nStart; *jGPGnSo
this.nEndPos = nEnd; (yfXMp,x
nThreadID = id; ]XY0c6 <
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4AJ9`1d4
} P>|Ef~j
v< Ty|(gd
K@HLIuz4t
public void run() W.IH#`-9E
{ cFw3Iw"JJ
while(nStartPos < nEndPos && !bStop) B+|IZoR
{ 2f `&WUe
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9g96 d-
try{ $-Cy
URL url = new URL(sURL); #o~[1K+Yq
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YjX*)Q_sl?
httpConnection.setRequestProperty("User-Agent","NetFox"); *g*VCO
String sProperty = "bytes="+nStartPos+"-"; FbmsN)mv!%
httpConnection.setRequestProperty("RANGE",sProperty); u9BjgK(M
Utility.log(sProperty); f0OgK<.>T
s~=g*99H
KLW&bJ$|j
InputStream input = httpConnection.getInputStream(); S3QaYq"v
//logResponseHead(httpConnection); 1}`2\3,
rJX\6{V!_
!F-sA: xq
byte[] b = new byte[1024]; _;#9!"&
int nRead; 2av*o~|J*:
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Zct!/u9 Q
{ z1#oWf{*
nStartPos += fileAccessI.write(b,0,nRead); ,^HS`!s[ E
//if(nThreadID == 1) (N7O+3+G
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ve6x/ PD
} SijS5irfk
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|g+!
Utility.log("Thread " + nThreadID + " is over!"); } +1'{B"I
bDownOver = true; sx:Hv1d
//nPos = fileAccessI.write (b,0,nRead); uQWp+}>ZJy
} 4AuH1m)<
catch(Exception e){e.printStackTrace ();} Ohi D
} v O PMgEI
} !n:uiwh
]b> pI;
(ZS/@He
//打印回应的头信息 wz h.$?~
public void logResponseHead(HttpURLConnection con) ~+=E"9Oo
{ UUGe"]V^g:
for(int i=1;;i++) YlrB@mE0n$
{ sLZ>v
String header=con.getHeaderFieldKey(i); Et.j1M|g
if(header!=null) ] ;&"1A
//responseHeaders.put(header,httpConnection.getHeaderField(header)); VJ*\pM@no
Utility.log(header+" : "+con.getHeaderField(header)); $3]b>v
else ~x\Cmu9`
break; lf6|.
} -( (Z@T1k
} Y|:YrZSC
,&[7u9@
$M39 #a
public void splitterStop() fy`+Efuj
{ ![).zi+m
bStop = true; o_(0
} oE6|Zw
4 A5t*e
>IBTBh_ka
} z,avQR&
X% X$Y6
P2t_T'R}
/* 1#q^uqO0
**FileAccess.java 3(C :X1
*//文件访问(定位，写) *<xrp*O
package NetFox; |_, /u_
import java.io.*; =q5@,wN^
vlu$!4I
/'\;8A$J`
public class FileAccessI implements Serializable{ +YuzpuxjJ
j %H`0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 SOs,)
RandomAccessFile oSavedFile; iE=P'"I
long nPos; 3p&jLFphL
Dp`HeSKU^
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public FileAccessI() throws IOException V~[:*WOX
{ ^SAq^3^P!
this("",0); "$DldHC
} :/i~y$t
=zOeb/
+6oG@
public FileAccessI(String sName,long nPos) throws IOException MJ\r 4n
{ pC^2Rzf
oSavedFile = new RandomAccessFile(sName,"rw"); B=dseeG[To
this.nPos = nPos; hiN/S|JN8y
oSavedFile.seek(nPos); :3 y_mf>
} C\A49q
!k-` eJ|
n,sY\=vB
public synchronized int write(byte[] b,int nStart,int nLen) `.8UKSH+
{ vhpvO>Q
int n = -1; (6clq:c7j
try{ K$ AB} Fvc
oSavedFile.write(b,nStart,nLen); cix36MR_
n = nLen; "{ FoA3g|
} :,^>d3k
catch(IOException e) C_Gzv'C"L
{ r.<JDdj
e.printStackTrace (); h)@InYwu7
} { 8p\Y
7wi%j!
az2Xch]
return n; {(Fe7,.S3
} W+hV9
;RHNRVP
Ia7D F'
} 4|f}F
N,|r1u9X#
7=3O^=Q^Q
/* IT&i,`cJ~F
**SiteInfoBean.java 1.0J2nZpt
*/ 9^\hmpP@D
package NetFox; J3IRP/*z
K'Spbn!nC
75AslL?t
public class SiteInfoBean { ~6HDW
-l[jEJS}
kFLT!k
private String sSiteURL; //Site's URL U&Ab#m;
private String sFilePath; //Saved File's Path oIxH3T
private String sFileName; //Saved File's Name 7P*Z0%Q
private int nSplitter; //Count of Splited Downloading File \O? u*
|_nC6;
+nQ!4
public SiteInfoBean() <T4(H[9B
{//nSplitter的缺省值为5 *8UYSA~v
//default value of nSplitter is 5 yoU2AMH2D^
this("","","",5); [pR)@$"k'
} Nb1J ~v
O9e.=l
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) TPK@*9rI
{ OZT^\Ky_l
sSiteURL= sURL; m^A]+G#/
sFilePath = sPath; i~8DSshA
sFileName = sName; jsdBd2Gdc
this.nSplitter = nSpiltter; :o$@F-$k
WIG=D{\Yx
qiU5{}
} xFwXW)
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^IgS
public String getSSiteURL() H%C\Uz"o
{ m}pL`:e!
return sSiteURL; ~p^7X2% !
} _[JkJwPTx
LzE/g)>
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public void setSSiteURL(String value) 1J'pB;.]s
{ v F[CWV.
sSiteURL = value; _.=`>%,
} bg1un@%!l
A$<>JVv
4 l1 i>_R
public String getSFilePath() QT;Va#a
{ |z+9km7,
return sFilePath; Q"'V9m7 i
} c _mq
n}:t<
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public void setSFilePath(String value) a[i>;0
{ lC2?sD$
sFilePath = value; sX5sL
} !&JiNn('
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r w\D>}\
public String getSFileName() yZ~b+=UM
{ <tW:LU(!
return sFileName; s ^3[W0hL
} RpAiU
avy=0Jmj
ENyAF%6
public void setSFileName(String value) 0T0/fg(o
{ N33AcV!*8
sFileName = value; ~?-qZ<9/
} FF3&Y^+^"
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tIp{},bQ^
public int getNSplitter() 4(8<w cL
{ "qgu$N4/>
return nSplitter; hv{87`L'K(
} &D)2KD"N
5}7ISNP;f
k#?|yP:
public void setNSplitter(int nCount) #Z!#;%S
{ k{{hZ/om
nSplitter = nCount; jiq2x\\!
} C/y(E|zC$
} *:[b'D!A
]<q'U> N
c(E,&{+E
/* |mvM@V;^8{
**Utility.java B#:E?a;{
*/ i3d y
package NetFox; gZ*hkKN6
EU9[F b]
aH
public class Utility { M2L0c?
`yx56
([tG y
public Utility() N"K\ick6J
{ p&uCp7]U
#?Wo <]i
"5h_8k~sQ
} Y6a$gXRT
);!dg\U
//线程睡眠 0H<4+ *`K
public static void sleep(int nSecond) Qj:{p5H'
{ ^^eV4Y5`+
try{ GeVc\$K-
Thread.sleep(nSecond); boIVU`F-!
} VT Vm7l
catch(Exception e) [*tU}9
{ L*v93;|s
e.printStackTrace (); a 1NCVZ
} ,;c{9H
} [{?;c+[
%~G0[fG
//日志 7fUi?41XA
public static void log(String sMsg) K# /Ch5?
{ _En]@xK3&
System.err.println(sMsg); \k4M{h6
} `k!UjO72
VSx%8IM+X
5qeT4| Ol
public static void log(int sMsg) z}D#WWSxf
{ a~6ztEhGm
System.err.println(sMsg); WVinP(#nfM
} C9GU6Ao
} FU'^n6[<B
]gEu.Nth`
H RWZ0 '
/* Qf"6PJ
**TestMethod.java 9*f2b.Aj
*/ JE/l#Q!
package NetFox; 7L1\1E:!
V2lp7"
Z"4VHrA
public class TestMethod { %}\ vW
3LT+9ad2d
Wn2Ny jX
public TestMethod() :~-)Sm+^
{ ///xx/weblogic60b2_win.exe C:WtCAm(
try{ \YjB+[.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _!|=AIX
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |+>%o.M&i
SiteFileFetch fileFetch = new SiteFileFetch(bean); UUZ6N ZQI
fileFetch.start(); 0c%@e2(N
} *;>V2!N=U
catch(Exception e){e.printStackTrace ();} -WQ_[t9l
z<FV1niE
Z3LQl(
} +#^sy>
#rqyy0k0'h
f_^ix
public static void main(String[] args) Z $ p^v*y
{ }G"r3*
new TestMethod(); mrhsKmH
} Wm];pqN
} 5d)'`hACe
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