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)); 3Tr}t.mt
} vX"jL
for(int i=0;i<nEndPos.length-1;i++) )\,hc$<=m
{ r2>y !Q?
nEndPos = nStartPos[i+1]; =!PUKa3f<
} ~aRcA|`
nEndPos[nEndPos.length-1] = nFileLength; Pna2IB+
} SLI358]$<
} [:-o;K\.-a
%~YQlN
($:JI3e[;
//启动子线程 &?B\(?*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; dG'5: ,n/
for(int i=0;i<nStartPos.length;i++) aW#_"Y}v'
{ fO$~jxR.
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K9f7,/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [bJAh ` I
nStartPos,nEndPos,i); %#b+ =J
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kR|(hA,$N
fileSplitterFetch.start(); T1pMe{
} Q5qQ%cu
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'C|yUsBC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~yuj;9m3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", CF+:9PG
nEndPos = " + nFileLength); ^LJ?GJ$g
// fileSplitterFetch[nPos.length-1].start(); L~xzfO
L[9]Ez$2+
e8<[2J)P&
//等待子线程结束 BFyVq
//int count = 0; WL5!H.q
//是否结束while循环 NX4}o&mDwn
boolean breakWhile = false; Gn%gSH/
-QUvd1S40
bAqaf#}e
while(!bStop) w/m~#`a
{ S[W|=(f9
write_nPos(); r)SwV!b
Utility.sleep(500); =1Mh%/y
breakWhile = true; $I-i=:}g
zSFqy'b.M-
xlWTHn!j
for(int i=0;i<nStartPos.length;i++) U i ~*]
{ x9!vtrM\Zr
if(!fileSplitterFetch.bDownOver) ,ZLg=
{ 7`f',ZK%
breakWhile = false; y-c2tF@'v
break; &D 4Ci_6k
} _GK3]F0
} kGSB6
if(breakWhile) H:HJHd"W
break; L'Fy\K\
A_WtmG_9
*FT )`
//count++; bqDHLoB\1
//if(count>4) Hc{0O7
// siteStop(); qSWnv`hL
} pZ4]oK\*
P$=Y5
yy6?16@
System.err.println("文件下载结束！"); "cUCB
} vc_ 5!K%[
catch(Exception e){e.printStackTrace ();} 2!35Tj"RFE
} $xf{m9 8
cSSrMYX2
Z{ A)
//获得文件长度 *OQr:e<}
public long getFileSize() G:2m)0bW
{ ;9hi2_luV
int nFileLength = -1; P]G`Y>#$r
try{ z@0*QZ.y1
URL url = new URL(siteInfoBean.getSSiteURL()); {~"6/L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +L86w7
httpConnection.setRequestProperty("User-Agent","NetFox"); R2af>R
Ibd na9z7
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int responseCode=httpConnection.getResponseCode(); iZ3%'~K<3J
if(responseCode>=400) Q7 Clr{&
{ C +%&!Q
processErrorCode(responseCode); zU'\r~c
return -2; //-2 represent access is error &&;ol}W
} .hxcx>%
|E)Es!dr
'MHbXFM
String sHeader; ''f07R
dik+BBu5z
N@>,gm@UU
for(int i=1;;i++) +)Pv6Zog[
{ ^vjN$JB
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); R;_U BQ)
//Utility.log(in.readLine()); ,rp-`E5ap
sHeader=httpConnection.getHeaderFieldKey(i); YEWHr>&Z
if(sHeader!=null) w-%H\+J
{ :_q
if(sHeader.equals("Content-Length")) ~iZMV ?w
{ btK| U
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;y7V-sf
break; @]#0jiS
} vRLkz4z
} i~dW)7
else ''Y}Q"
break; ?5#Ng,8iT
} 64^dy V,;
} ;u'mSJI'
catch(IOException e){e.printStackTrace ();} tZ]|3wp
catch(Exception e){e.printStackTrace ();} *JX)q
-BNlZgk-^
|yi3y `f
Utility.log(nFileLength); Ok+zUA[Wu
'|b {
q9RCXo>Y+1
return nFileLength; d]OoJK9&&
} bc"E=z
}TZ5/zn.Dw
B8^tIq
//保存下载信息（文件指针位置） 3:i4DBp,i
private void write_nPos() bUC-}
{ fn zj@_{|
try{ @xJ qG"
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9lA@ K[
output.writeInt(nStartPos.length); PnsQ[}.
for(int i=0;i<nStartPos.length;i++) E/<[G?
{ 8=!M0i
// output.writeLong(nPos); ?=]`X=g6
output.writeLong(fileSplitterFetch.nStartPos); k[l+~5ix
output.writeLong(fileSplitterFetch.nEndPos); h94SLj]
} ~ySmN}3~'
output.close(); r3l}I6
} _dj<xPO
catch(IOException e){e.printStackTrace ();} jGzs; bE
catch(Exception e){e.printStackTrace ();} *J!oV0#1
} \`#;J?Y|`F
2hV#3i
{4 !%'~
//读取保存的下载信息（文件指针位置） 22\Buk}?
private void read_nPos() FDaHsiI:
{ AC=cz!3iB
try{ \^kyC1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ^lT$D8
int nCount = input.readInt(); aW7{T6.,
nStartPos = new long[nCount]; )^uLZMNaI
nEndPos = new long[nCount]; $jb0/
for(int i=0;i<nStartPos.length;i++) N:!XtYA<
{ BJk:h-m [
nStartPos = input.readLong(); 0}qij
nEndPos = input.readLong(); />XfK,c-
} Z&=K+P
input.close(); BBw`8!
} L`YnrDZK
catch(IOException e){e.printStackTrace ();} .Lo$uKsW$l
catch(Exception e){e.printStackTrace ();} I]>-~_
} YH^_d3A;
d3T|N\(DL
(|Am
private void processErrorCode(int nErrorCode) }$V]00 X
{ 5j`"@C5;O
System.err.println("Error Code : " + nErrorCode); $"T1W=;j9
} p2PD';"
[UquI "
j3VM!/
//停止文件下载 []0`>rVq
public void siteStop() 6hYv
{ 2](R}
bStop = true; !&TbE@Xk
for(int i=0;i<nStartPos.length;i++) U KF/v
fileSplitterFetch.splitterStop(); qt}vM*0}V
}1w[G;$
A6}M F
} *Xt#04_
} r_]wa
//负责部分文件的抓取 \~Zj](#
**FileSplitterFetch.java RMDs~
*/ m?xzx^xs/
package NetFox; !,Wd$UK
7|T<dfQk
%96JH YcX
import java.io.*; {$>*~.Wu
import java.net.*; OekcU%C
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public class FileSplitterFetch extends Thread { knpb$eX4
X#5dd.RR
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String sURL; //File URL "*#$$e53A
long nStartPos; //File Snippet Start Position ppVjFCv0<
long nEndPos; //File Snippet End Position BgD;"GD*W
int nThreadID; //Thread's ID h|dVVCsN
boolean bDownOver = false; //Downing is over jgYUS@}
boolean bStop = false; //Stop identical d6<,R;)
FileAccessI fileAccessI = null; //File Access interface u.0Z)j}N
{gl-tRC3
][:6En}
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _x z_D12
{ E3.=|]W'
this.sURL = sURL; JJ,Fh .
this.nStartPos = nStart; 0F`@/C1y55
this.nEndPos = nEnd; E@"+w,x)
nThreadID = id; ?AyG!F
fileAccessI = new FileAccessI(sName,nStartPos);//定位 'rHkJ
} Iqe4O~)
%B3E9<9>U
b0x9}
public void run() Xgd!i}6Q
{ {8Hrb^8!
while(nStartPos < nEndPos && !bStop) 17H_>a\`
{ 1@E<5rp o
:^3MN
5h+g^{BE
try{ M\,0<{
URL url = new URL(sURL); 5)V J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <X j:c2@
httpConnection.setRequestProperty("User-Agent","NetFox"); WDY,?
String sProperty = "bytes="+nStartPos+"-"; (p68Qe%OuG
httpConnection.setRequestProperty("RANGE",sProperty); Lh"Je-x<<
Utility.log(sProperty); @= 6}w_
O\XN/R3
,y,NVF
InputStream input = httpConnection.getInputStream(); i+Px &9o<9
//logResponseHead(httpConnection); h -+vM9j
!zvKl;yT
;_of'
byte[] b = new byte[1024]; waQNX7Xdn
int nRead; }Nl-3I.S^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) E92dSLhs5
{ <y6M@(b
nStartPos += fileAccessI.write(b,0,nRead); ;QW6Tgt11
//if(nThreadID == 1) v(FO8*5DZ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Dq*>+1eW2
} !s?vj <
'7 6}6G%
nBaY|
Utility.log("Thread " + nThreadID + " is over!"); q*@7A6:FV>
bDownOver = true; YQ4;X8I`r
//nPos = fileAccessI.write (b,0,nRead); 9,82Uta
} ??aOr*%
catch(Exception e){e.printStackTrace ();} <QugV3e
} !a~>;+
} P00d#6hPJ
7}%3Aw6]S
^g~Asz5]
//打印回应的头信息 -}MWA>an8
public void logResponseHead(HttpURLConnection con) C:_!zY'z
{ %xyt4}-)m
for(int i=1;;i++) aoco'BR F
{ _z)G!_7.>\
String header=con.getHeaderFieldKey(i); |`U^+Nf
if(header!=null) nC qUg_{D
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,78QLh9:
Utility.log(header+" : "+con.getHeaderField(header)); my[)/'
else niFX8%<hP
break; UALwr>+VJ
} WA8Qt\Q
} 6WgGewn
/+"BU-aQk
>wdR4!x!?
public void splitterStop() `{N0+n
{ ZJ 8~f
bStop = true; W.-[ceM
} <!Nj2>
rV"<1y:g
,@/b7BVv
} `U#*O+S-^
PGP9-M
"T<Q#^m
/* |5Mhrb4.
**FileAccess.java 3:YZC9
*//文件访问(定位，写) R8c1~'
package NetFox; :v* _Ay
import java.io.*; Ol~sCr
s IY`H^
y!1%Kqx1,n
public class FileAccessI implements Serializable{ f/&Dy'OV7
:w#Zs)N
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ya5;C"
RandomAccessFile oSavedFile; pTST\0?
long nPos; {Rc/Ten
&%>l9~F'~
37v!:xF!
public FileAccessI() throws IOException gJ+MoAM"
{ .2C}8GGC'
this("",0); gvr"F
} >E#| H6gx
y)"aQJ>
Qa5<go{
public FileAccessI(String sName,long nPos) throws IOException cnnlEw/&
{ 3:PBVt=
oSavedFile = new RandomAccessFile(sName,"rw"); iJZqAfG{m?
this.nPos = nPos; ;jfjRcU
oSavedFile.seek(nPos); 0X~
} TixHEhw
gkI(B2,/
mSY;hJi
public synchronized int write(byte[] b,int nStart,int nLen) Ss@\'K3e
{ PQa{5"
int n = -1; KX"?3#U#Fm
try{ ;? '`XB!
oSavedFile.write(b,nStart,nLen); %q;3bfq@N
n = nLen; R."<he ;
} {[jcT>.3j
catch(IOException e) 5H6m{ng
{ 0F1 a
e.printStackTrace (); drBWo|/
} 54JZEc
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return n; H\Y.l,^
} )p~\lM}?d
d0Py[37V
7Z0 )k9*
} ~Hd{+0
k v,'9z
`ihlKFX
/* `pn]jpW9
**SiteInfoBean.java ua/A &XQx
*/ ecA:y!N
package NetFox; g:dw%h
mv/'H^"[_
`4'v)!?
public class SiteInfoBean { NN\% X3ri"
lf4-Ci*X
k_r12Bu
private String sSiteURL; //Site's URL pD9*WKEf*
private String sFilePath; //Saved File's Path yc8iT`
private String sFileName; //Saved File's Name (*;b\h
private int nSplitter; //Count of Splited Downloading File we4e>)
8Focs p2
TbXp%O:[W
public SiteInfoBean() )TP1i
{//nSplitter的缺省值为5 -;a}'1HOE
//default value of nSplitter is 5 Ett%Y*D+J
this("","","",5); (x@|6Sb
} /1zi(z
\L}Soe'
f>s3Q\+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !e?=I
{ *TfXMN?w
sSiteURL= sURL; awB1ryrOF
sFilePath = sPath; 89v9BWF
sFileName = sName; DxdiXf[j
this.nSplitter = nSpiltter; j5Vyo>
:7KcD\fCj
\zR@FOl`q
} ()6(eRGJ
{CG%$rh
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public String getSSiteURL() Zgkk%3'^'
{ "EQ`Q=8
return sSiteURL; cgNK67"(
} v(W$\XH
JfxD-9U^>u
hk3}}jc
public void setSSiteURL(String value) 3BAls+<p o
{ q!\K!W\
sSiteURL = value; \rn:/
} s$4!?b$tw
)[|TxXz d
{" woBOaA
public String getSFilePath() (n;#Z,
{ jAB~XaT,
return sFilePath; o9(:m
} Wz)s#
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public void setSFilePath(String value) $ jWe!]ASU
{ 2 DJs'"8
sFilePath = value; 7m~.V[l1
} \XFF(
yDg`9q.ckm
eU&[^
public String getSFileName() 2a'b}<|[(
{ ekND>Qjj
return sFileName; 8iaP(*J
} rz+)z:u
l tE`
.|^L\L(!
public void setSFileName(String value) HJ?p,V q5_
{ -f@~{rK.L
sFileName = value; &\#If:
} I(y:Td
4/vQ/>c2j
.;&c<c|
public int getNSplitter() lK;|ciq"c7
{ ;|*o^9q
return nSplitter; F`IV9qv
} |re)]%A?Fu
141@$mMzE
P /|2s
public void setNSplitter(int nCount) J5e
{ [vh&o-6
nSplitter = nCount; c}v>Mx
} ZFpi'u.&
} )65 o
<Dojl #
5V5Nx(31i
/* .`*h2
**Utility.java Y` t-Bg!~
*/ Teh _
package NetFox; -XBD WV
i,|2F9YH
`d]D=DtH
public class Utility { ;}"!|
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public Utility() @c,Qj$\1
{ fGS5{dti
&v9*D`7L
5q4sxY9T
} WX<),u2@
+)YU/41W
//线程睡眠 tk=~b}8
public static void sleep(int nSecond) z0|%h?N
{ 'b(V8x
try{ 4UP#~
Thread.sleep(nSecond); 6?\X)qBI
} h[HFZv~{
catch(Exception e) ?=$=c8xw
{ (jhDO7
e.printStackTrace (); j0P+<@y
} zv/owK
} Y,0D+sO4
K@d,8[
//日志 %Y!31oC#
public static void log(String sMsg) |hGi8
{ kD1[6cJ!=.
System.err.println(sMsg); +9Vp<(
} kq+`.
p+6L qk<
P(h[QAM
public static void log(int sMsg) ^}Vx5[
{ EhJpJb[Z
System.err.println(sMsg); -aj) _.d
} 3s25Rps
} h|m>JDxn
\ k&(D*u
o+-G@16
/* Nr6[w|Tzd
**TestMethod.java ~t0\Q; @($
*/ *F[;D7sZ~
package NetFox; 3pQ^vbQ"
Qmbl_#
9qe<bds1
public class TestMethod { JSKAlw
+E5EOo{ `|
W[ZW=c
public TestMethod() 2g'o5B\*
{ ///xx/weblogic60b2_win.exe /D@(o`a
try{ )Pj8{.t4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); lxSCN6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #\DKU@|h
SiteFileFetch fileFetch = new SiteFileFetch(bean); cow]qe6K
fileFetch.start(); "WPFZw:9
} WBOebv
catch(Exception e){e.printStackTrace ();} BBkYc:B=SA
o]gS=iLp
UB5X2uBv
} [*i6?5}-
znVao %b
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public static void main(String[] args) *21foBfqh
{ 7R4xJ H
new TestMethod(); .|d2s
} <OR f{
} -XcX1_
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