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)); WxS=Aip'
} 'k9hzk(*
for(int i=0;i<nEndPos.length-1;i++) S-:7P.#Q
{ {@u}-6:wAT
nEndPos = nStartPos[i+1]; m 5NF)eL
} x6x6N&f?
nEndPos[nEndPos.length-1] = nFileLength; s!E-+Gw
} ^Y:Q%?uB/
} zA/W+j$:
pPG@_9qf
`|^<y.-6
//启动子线程 E4'D4@\W
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; '#.:%4
for(int i=0;i<nStartPos.length;i++) B&m?3w
{ 6YZ&>`a^
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wzMWuA4vX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Ye}y_W
nStartPos,nEndPos,i); VrokEK*qbY
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }m<)$.x|P
fileSplitterFetch.start(); dMwVgc:
} XjwTjgL<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `<>8tZS9"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); A{E0 a:v
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Y4Z?`TL
nEndPos = " + nFileLength); Xklp6{VH9
// fileSplitterFetch[nPos.length-1].start(); NwG&uc+Q
[VPqI~u5)
ZtEHP`Iin
//等待子线程结束 HC8{);
//int count = 0; V_(?mC
//是否结束while循环 !+M H?A
boolean breakWhile = false; 6iFd[<.*j
#V8='qD
,9#G/nF
while(!bStop) ANCgch\
{ {Pg7IYjH
write_nPos(); V]PTAhc
Utility.sleep(500); M{7EFTy!y
breakWhile = true; _pNUI{De
`z3?ET
kx1-.~)p(z
for(int i=0;i<nStartPos.length;i++) Y#6@0Nn[G
{ ^D B0C
if(!fileSplitterFetch.bDownOver) T"Q4vk,3*J
{ l{Hi5x'H
breakWhile = false; .@APxeU
break; "MXd!
} ;8g#"p*&
} Vb 4Qt#o
if(breakWhile) ~pj9_I
break; US7hKNm.
(>0d+ KT
-lMC{~h\(S
//count++; zPV/{)S
//if(count>4) G-n`X":$DT
// siteStop(); z6G^BaT'
} ~|J6M
W{;!JI7;z
r+0)l:{.
System.err.println("文件下载结束！"); HXdPKS4q
} O|j5ulO}&"
catch(Exception e){e.printStackTrace ();} 8XJ%Yuu
} ^[%~cG
J7QlGm,=
/,0t,"&Aqa
//获得文件长度 z4-AOTo2y
public long getFileSize() 3<+l.Wly
{ l}(~q!r
int nFileLength = -1; V6$v@Zq
try{ 6g$04C3tHi
URL url = new URL(siteInfoBean.getSSiteURL()); ~*B1}#;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >/bl r}5 H
httpConnection.setRequestProperty("User-Agent","NetFox"); lGLZIp
RFK N,oB
\0WMb
int responseCode=httpConnection.getResponseCode(); (I[o;0w
if(responseCode>=400) t41cl
{ ?o.G@-
processErrorCode(responseCode); =,@SZsM*B
return -2; //-2 represent access is error jQ`"Op 3
} Op%^dwVG(v
u khI#:[
@/0aj
String sHeader; 6xFZv t
(tq)64XVz
9D#PO">|
for(int i=1;;i++) yl'~H;su
{ RycEM|51V
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); WejY b;KS
//Utility.log(in.readLine()); W&!Yprr
sHeader=httpConnection.getHeaderFieldKey(i); 2qr%xK'^B
if(sHeader!=null) N'`*#UI+
{ n1ED _9
if(sHeader.equals("Content-Length")) 6:EO
{ 7GP?;P
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); iqoPD4A
break; Nl@Hx
} t'Q48QAb?
} _ _)Z Q
else XPEjMm'*b3
break; akqXh 9g
} `a6;*ry
} tcX7Ua(I`
catch(IOException e){e.printStackTrace ();} 95!xTf
catch(Exception e){e.printStackTrace ();} "Z{^i3gN
v;$^1I
nlmkkTHF8
Utility.log(nFileLength); I'@ }Yjm|
@s IZ
*Cb(4h-
return nFileLength; q$t& *O_
} 0Hz3nd?v
GS{9MGl
Ti)n(G9$
//保存下载信息（文件指针位置） 0"QE,pLe4
private void write_nPos() 7CIje=u.q
{ g]ihwm~
try{ ,5\n%J:
output = new DataOutputStream(new FileOutputStream(tmpFile)); gEe}xI
output.writeInt(nStartPos.length); 2)8lJXM$L
for(int i=0;i<nStartPos.length;i++) k{bba=<
{ q/3}8BJ
// output.writeLong(nPos); 8EE7mEmLH
output.writeLong(fileSplitterFetch.nStartPos); 3Q]MT
output.writeLong(fileSplitterFetch.nEndPos); q@!:<Ra,){
} b]Y,& 8}[+
output.close(); & aLR'*]6
} OKU P
catch(IOException e){e.printStackTrace ();} SA&wW\Ym]
catch(Exception e){e.printStackTrace ();} n)=&=Uj`f
} \D[BRE+
vB Jva8;Q
B#DV<%GPl
//读取保存的下载信息（文件指针位置） 7uDUZdJy
private void read_nPos() vn_avYwiy
{ 9qW,I|G
try{ X%-4x
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); WIGb7}egR
int nCount = input.readInt(); t!=S[
nStartPos = new long[nCount]; <7&b|f$CL
nEndPos = new long[nCount]; k@Tt,.];
for(int i=0;i<nStartPos.length;i++) cnc$^[c
{ H{XW?O^@
nStartPos = input.readLong(); @<PL
nEndPos = input.readLong(); 4Oy c D
} _YJwF1e+M
input.close(); NWpRzh8$u
} j>T''Tf
catch(IOException e){e.printStackTrace ();} !^7:Rr_
catch(Exception e){e.printStackTrace ();} [Vf|4xcD
} m88~+o<G%
1)R)+`y
z%KChU
private void processErrorCode(int nErrorCode) Qh[t##I/
{ H xlw1(zS
System.err.println("Error Code : " + nErrorCode); 1,QRfckks
} Xm4wuX"e=
QXz!1o+"
S&Sf}uK
//停止文件下载 zXD@M{
public void siteStop() 4[ra
{ S'O0'5U@
bStop = true; JU@$(
for(int i=0;i<nStartPos.length;i++) + ND9###
fileSplitterFetch.splitterStop(); .3&m:P8zV
<D^x6{}
%;5hHRA
} H5AY6),
} OS 6 )`
//负责部分文件的抓取 s7e'9Bx
**FileSplitterFetch.java hJ<2bgQo
*/ @CmxH(-i-
package NetFox; {2x5 V#6
B<R-|-#
hmH$_YP}
import java.io.*; qWFg~s#+
import java.net.*; cTnbI4S;
vy#(|[pL{
f+6l0@K2
public class FileSplitterFetch extends Thread { GCKl[<9*
US|vYd}u+
0o]K6b
String sURL; //File URL >+#[O"
long nStartPos; //File Snippet Start Position f3>/6C
long nEndPos; //File Snippet End Position ,2`d3u^CW
int nThreadID; //Thread's ID {5udol5?
boolean bDownOver = false; //Downing is over jveRiW@
boolean bStop = false; //Stop identical @\y7 9FX
FileAccessI fileAccessI = null; //File Access interface P1QJ'eC;T
Kq$Zyf=E
ie!4z34
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `9+EhP$RS
{ 3EvA 5K.
this.sURL = sURL; #+;=ijyF
this.nStartPos = nStart; taQ[>x7b
this.nEndPos = nEnd; T_uuFL
nThreadID = id; O5Lv:qAa
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;]Aa
} YiTp-@$}
t}7wRTG
a{+oN $
public void run() DR /)hAE
{ vt N5{C
while(nStartPos < nEndPos && !bStop) >I?Mi{'a
{ "{_"NjH
^H4iHjg
A 5 X+Z
try{ .y/b$|d,
URL url = new URL(sURL); $D5U#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2YKM9Ks
httpConnection.setRequestProperty("User-Agent","NetFox"); SDIeq
String sProperty = "bytes="+nStartPos+"-"; 4AYc8Z#'
httpConnection.setRequestProperty("RANGE",sProperty); Xoy1Gi?
Utility.log(sProperty); zq.&Mw?
v+#j>
dYd~9
InputStream input = httpConnection.getInputStream(); <.b$ gX
//logResponseHead(httpConnection); |S{P`)z%f
\6hL W_q1
Q/c WV
byte[] b = new byte[1024]; hD1AK+y
int nRead; Wts{tb
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) GZEonCk[&
{ (J&Xo.<Z-
nStartPos += fileAccessI.write(b,0,nRead); 4E>(Y98
//if(nThreadID == 1) _,FoXf7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~8(X@~Tn*
} dSVu_*y
k~f+LO
j9}0jC2Tb
Utility.log("Thread " + nThreadID + " is over!"); NE3wui1 V
bDownOver = true; p*,P%tX
//nPos = fileAccessI.write (b,0,nRead); :XSc#H4
} 0 '7s
catch(Exception e){e.printStackTrace ();} wW8 6rB
} rfRo*u2"
} N[bN"'U/1
=h::VB}Lv
&ZN'Ey?
//打印回应的头信息 0:'jU
public void logResponseHead(HttpURLConnection con) >iH).:j
{ yZp:hs#
for(int i=1;;i++) VaSNFl1_M
{ wLSZL
String header=con.getHeaderFieldKey(i); x{>Y$t]
if(header!=null) jF{gDK
//responseHeaders.put(header,httpConnection.getHeaderField(header)); &&1Y"dFs
Utility.log(header+" : "+con.getHeaderField(header)); $|(|Qzi%
else S7ehk*`
break; xzl4v=7
} I~LQ1_
} F/*fQAa"
}Tr83B|
x7Rq|NQ
public void splitterStop() s2?,'es
{ :.o=F`W
bStop = true; =jIT"rk
} V`,[=u?c
R}wwC[{
d Zz^9:C+
} p@8krOo`
qM>OE8c#/
{Okik}Oh
/* o+-Ge J
**FileAccess.java >|/? Up
*//文件访问(定位，写) on;sq8;
package NetFox; fsJTwSI["
import java.io.*; #)mkD4
A Ok7G?Y
V87ee,
public class FileAccessI implements Serializable{ 9`CiE
$qtU
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /-{O\7-D
RandomAccessFile oSavedFile; wGzXp5 dl
long nPos; e0N=2i?I#z
#4_O;]{'
7tl)4A6
public FileAccessI() throws IOException k]$E8[.t
{ M-Z6TL
this("",0); $sc8)d\B
} y:|.m@ j1
?Y0$X>nm
! jX+ox
public FileAccessI(String sName,long nPos) throws IOException nhP~jJn
{ I"Q9W|J_&
oSavedFile = new RandomAccessFile(sName,"rw"); ;/";d]j
this.nPos = nPos; e,#+Xx0M
oSavedFile.seek(nPos); 9SH<d)^
} %<=vbL9
9(^X2L&Z
_N,KHxsG8B
public synchronized int write(byte[] b,int nStart,int nLen) O5TK&j
{ 1x\W521
int n = -1; &Qq/Xi,bZ
try{ Eo {1y
oSavedFile.write(b,nStart,nLen); }U?gKlLg
n = nLen; p21=$?k!;
} krr-ZiK
catch(IOException e) D2TXOPH
{ SJ@8[n.x
e.printStackTrace (); yToT7 X7F7
} e1`)3-f
+%e%UF@
4('0f:9z+
return n; GwMUIevO_
} .}$`+h8WT
Y1yXB).AH8
\}u7T[R=`
} Owh*KY:
igRDt{}
^i`3cCFB<
/* xyS2_Q
**SiteInfoBean.java 8V=HyF#
*/ v E3{H
package NetFox; !X\sQNp
C NzSBm
} Jdh^t.
public class SiteInfoBean { (}*\ {
F;?TR[4!k
(EOec5qXU
private String sSiteURL; //Site's URL ]xJ'oBhy
private String sFilePath; //Saved File's Path ^Kw&=u
private String sFileName; //Saved File's Name a8bX"#OR&N
private int nSplitter; //Count of Splited Downloading File :\1rQT
2\nBqCxR
uGP[l`f|FQ
public SiteInfoBean() X|-v0 f
{//nSplitter的缺省值为5 (5Z8zNH`3
//default value of nSplitter is 5 8g# c%eZ
this("","","",5); c6?c>*z
} F;d%@E_Bc
.`p<hA)%[C
YoV^xl6g
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7zJrT5
{ F,L82N6\U
sSiteURL= sURL; R<y Nv
sFilePath = sPath; ,`%k'ecN
sFileName = sName; @wYQLZ
this.nSplitter = nSpiltter; PEX26==
_q$0lqq~u
%2@ Tj}xa
} |z!q r}i
Q QsVIHA
{UX"Epd);n
public String getSSiteURL() 5bF9IH
{ ]689Q%D
return sSiteURL; H7z>S G0
} AQnJxIL:
~J:$gu~`
{dy` %It
public void setSSiteURL(String value) a2cx
{ c]s(u+i
sSiteURL = value; a!c/5)v(
} eEWroF
r%g <hT 8
E(aX4^]g
public String getSFilePath() ";-{~
{ 7X9+Qj;
return sFilePath; $I)Tk`=
} V!pq,!C$v
gD,YQ%aq
vF.?] u
public void setSFilePath(String value) Vr&el
{ RR[)UQ
sFilePath = value; i$`|Y*
} vKU]80T
dp"<KcP_
]97Xu_
public String getSFileName() ;-3h~k
{ i63`B+L{
return sFileName; 9_J!s
} N<L$gw+)$D
q;~R:}?@
bGGeg%7
public void setSFileName(String value) 4B:\
{ &57qjA,8<
sFileName = value; sowbg<D
} `!UaScM
uD.
qO:U]\P
public int getNSplitter() {Ior.(D>Y
{ zVp[YOS&c
return nSplitter; jGk7=}nw
} 92P,:2`a
3n.+_jQ>s
th.M.jas
public void setNSplitter(int nCount) k1^V?O
{ S`pF7[%rp
nSplitter = nCount; !6XvvTs/<
} +l2e[P+qA
} /p"U
g6rv`I$l
RE ![O
/* Du)B9s
**Utility.java T$gkq>!j<E
*/ KW&nDut
package NetFox; vqrBRlZ
YYTO,4
"_nX5J9
public class Utility { +G5'kYzJ
4ggVj*{v
z{Hz;m:*_
public Utility() $?H]S]#|}.
{ M?E9N{t8)a
_Ct}%-,4
Q;XXgX#l
} fl!mYCPv
#[no~&E
//线程睡眠 C#A@)>
public static void sleep(int nSecond) )v${&H
{ &tlR~?$e*
try{ fswZM\@
Thread.sleep(nSecond); Eem 2qKj
} M.o?CX'
catch(Exception e) ,$HHaoog
{ ,3G$`
e.printStackTrace (); Zr\2BOcc.l
} fdd~e52f
} "F&Tnhh4
LTg?5GwD\j
//日志 \ua9thOG
public static void log(String sMsg) kFS0i%Sr
{ &(lMm)
System.err.println(sMsg); 11i"nR|
} 8&?^XcJ*x
^bF}_CSE
~wfoK7T}
public static void log(int sMsg) k%"$$uo
{ ]MC/t5vCu
System.err.println(sMsg); 6o$Z0mG
} iYkRo>3!QX
} "EJ\]S]$X
OZ eiHX!
8r2XGR
/* Xyb8u})p'
**TestMethod.java K3La9O)>
*/ +nU',E
package NetFox; Xfj)gPt}
kBrvl^D{5
`2pO5B50
public class TestMethod { jeY4yM
FL59
l#b:^3
public TestMethod() 4+)Zk$E
{ ///xx/weblogic60b2_win.exe 72`/d`
try{ ymHKcQ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); bAUHUPe
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0rV/qMo;K
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2q+la|1Cr
fileFetch.start(); DKR<W.!*t
} [.M
catch(Exception e){e.printStackTrace ();} ty':`)
QyTh!QM~`
h!QjpzQe
} x]H3Y3
}K?F7cD
)sqaR^
public static void main(String[] args) 8^i[j\Y;6
{ 5@K\c6
new TestMethod(); bC6X?m=
} c qv.dC
} L%f-L.9`u
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