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)); :h1pBEiH
} 99EXo+g
for(int i=0;i<nEndPos.length-1;i++) &''WRgZ}
{ 9*:gr#(5
nEndPos = nStartPos[i+1]; RJeSi`19T)
} zT ZVehEe
nEndPos[nEndPos.length-1] = nFileLength; ;;)`c/$
} /Ky__l!bu
} Y\=FLO9
DKmZ
! <WBCclX
//启动子线程 fKtV'/X;Q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1h7+@#<:a
for(int i=0;i<nStartPos.length;i++) A!63p$VT;
{ 8by@iQ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]P[%Mhg^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Yif*"oO
nStartPos,nEndPos,i); -]:GL>b
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tMj1~ R
fileSplitterFetch.start(); Q# ?wXX47
} O3o: qly!
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jtm?z c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); a8AYcEb
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", },[;O^Do^{
nEndPos = " + nFileLength); +!0eu>~_&
// fileSplitterFetch[nPos.length-1].start(); gf)t)-E
jKIc09H|
l\$+7|W
//等待子线程结束 [hRU&z;W
//int count = 0; ;PyZ?Z;
//是否结束while循环 Ei({`^
boolean breakWhile = false; ,572n[-q
D,ly#Nn
rgcWRt
while(!bStop) (ozb%a#B
{ nF)uTk
write_nPos(); efz&@|KR
Utility.sleep(500); nkeI60
breakWhile = true; ] q~<=
AKu_~bTk
xeTgV&$@
for(int i=0;i<nStartPos.length;i++) l|/:Ot
{ Z"I/ NGiU
if(!fileSplitterFetch.bDownOver) MQcr^Y_
{ |Wj;QO$C
breakWhile = false; \0FT!} L
break; f0Hq8qAF;^
} y:}sD_m0W
} {fSfq&o
if(breakWhile) 1q.(69M
break; p D=w>"
tu%[p 4
]qw0V
//count++; bZipm(e
//if(count>4) ")lw9t`
// siteStop(); .+K S`
} B>TSdn={>
D!TZI
gY9\o#)<
System.err.println("文件下载结束！"); +'03>!V
} J7i+c];!<
catch(Exception e){e.printStackTrace ();} g.Hio.fVd
} :wgfW .w
-g`IH-B
J^3H7 ]
//获得文件长度 vH?9\3
public long getFileSize() O%1/r*
{ q'(z #h,cv
int nFileLength = -1; {)K](S ~
try{ FEm=w2
URL url = new URL(siteInfoBean.getSSiteURL()); =7ydk"xM*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eXy"^xp^
httpConnection.setRequestProperty("User-Agent","NetFox"); XrN- 2HTV
B/eaqJ
_|,{ ^m|d
int responseCode=httpConnection.getResponseCode(); =K$,E4*
if(responseCode>=400) _dU P7H (
{ Nf?\AK!
processErrorCode(responseCode); LAZVW</
return -2; //-2 represent access is error [>w%CY<Fd
} 5 d ;|=K
r[HT9
w+f=RHX"{
String sHeader; O]nT>;PXX
RIhOR8)
Q;26V4
for(int i=1;;i++) E`@43Nz
{ F,v7ifo#f
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); OV5e#AOy)
//Utility.log(in.readLine()); ESDB[ O+`x
sHeader=httpConnection.getHeaderFieldKey(i); :):zNn_>`
if(sHeader!=null) VO`"<
{ bsO@2NP'
if(sHeader.equals("Content-Length")) 8sw,k
{ HcJE0-"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); l C\E
break; wq72%e
} W(&6
} 9qH[o?]
else 3ps,uozj
break; C{Blqf3V0
} 5}a"?5J^
} \f"?Tv-C'
catch(IOException e){e.printStackTrace ();} N8+P
catch(Exception e){e.printStackTrace ();} ,k*F`.[
&=-PRza%j
o'qm82* =
Utility.log(nFileLength); vR]mSX3)?
u@D.i4U
GNghB(
return nFileLength; .[f;(WR
} |U=(b,
jzrt7p*k}
6An{3"
//保存下载信息（文件指针位置） `$-lL"
private void write_nPos() dt~iw
{ :dDxxrs"
try{ aIu2>
output = new DataOutputStream(new FileOutputStream(tmpFile)); my,x9UPs
output.writeInt(nStartPos.length); j-* TXog
for(int i=0;i<nStartPos.length;i++) c$#GM57V
{ .3g&9WvN!Z
// output.writeLong(nPos); ;c)! @GoA
output.writeLong(fileSplitterFetch.nStartPos); v*L '{3f
output.writeLong(fileSplitterFetch.nEndPos); lO&cCV;
} rv?!y8\
output.close(); !`C%Fkq
} e\~l!f'z
catch(IOException e){e.printStackTrace ();} {8ECNQ[]
catch(Exception e){e.printStackTrace ();} Uh\]?G[G
} (C~dkR?
(rMZ
2f`xHI/@fj
//读取保存的下载信息（文件指针位置） >a9l>9fyY
private void read_nPos() -kc(u1!
{ qC.i6IL
try{ 0Bu*g LY
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); kJeu40oN
int nCount = input.readInt(); 6J;i,/ky
nStartPos = new long[nCount]; h,hL?imD
nEndPos = new long[nCount]; 1(pjVz&
for(int i=0;i<nStartPos.length;i++) +:y&{K
{ lA4hm4"i(,
nStartPos = input.readLong(); &(0N.=R
nEndPos = input.readLong(); L?.7\a@
} _3U|2(E
input.close(); l4Y1(
} "7?t)FOo
catch(IOException e){e.printStackTrace ();} !VNbj\Bp
catch(Exception e){e.printStackTrace ();} O*4gV}:G
} H%~Q?4
6JWGu/A
U6a zhi&,
private void processErrorCode(int nErrorCode) !5E9sk{)
{ .~22^k
System.err.println("Error Code : " + nErrorCode); 6puVw-X
} q]+)c2M
i;avwP<0
S[.5n]
//停止文件下载 TnxU/)
public void siteStop() 9C>ynH
{ qSR?,G
bStop = true; X?kPi&ru
for(int i=0;i<nStartPos.length;i++) 1!f2*m
fileSplitterFetch.splitterStop(); LK %K0o
@?vLAsp\
xBt<Yt"
} `rq<jtf+
} X{s/``n
//负责部分文件的抓取 (L:`ojiU
**FileSplitterFetch.java 'XEK&Yi1
*/ #!Ze\fOC
package NetFox; ?KCxrzf
x57'Cg \
-sx-7LKi
import java.io.*; VlV)$z_
import java.net.*; <%/:w/
:SQLfOQ
bCt_yR
public class FileSplitterFetch extends Thread { w0$R`MOR+
w@2~`<Hk'"
tNYJQ
String sURL; //File URL u IF$u
long nStartPos; //File Snippet Start Position 6_Fpca3L
long nEndPos; //File Snippet End Position UMv"7~
int nThreadID; //Thread's ID 0tSA|->(
boolean bDownOver = false; //Downing is over j]#wrm
boolean bStop = false; //Stop identical 5(KG=EHj_
FileAccessI fileAccessI = null; //File Access interface $Llvp bl
b_ypsGE]5!
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException G+fd.~aGE
{ (}6wAfGo
this.sURL = sURL; oq243\?Y
this.nStartPos = nStart; .?70=8{
this.nEndPos = nEnd; B0S8vU
nThreadID = id; N]V/83_
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >|5XaaDa
} xdCs5ko
5UPPk$8`
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public void run() z?I+u*rF6
{ Mo~ki"9.
while(nStartPos < nEndPos && !bStop) sb`&bA;i
{ P~o@9RV-
(}sDm~;s
$e>/?Ss
try{ _qEWu Do
URL url = new URL(sURL); 5a8JVDLX^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p[_Yi0U
httpConnection.setRequestProperty("User-Agent","NetFox"); pEY>A_F
String sProperty = "bytes="+nStartPos+"-"; M9h<}mh\
httpConnection.setRequestProperty("RANGE",sProperty); HUK"OH
Utility.log(sProperty); (K<Z=a
Tln9q0"W
w<v1N
InputStream input = httpConnection.getInputStream(); _F3KFQ4,S-
//logResponseHead(httpConnection); `B:B7Cpvn
(/('nY
2B5A!?~>
byte[] b = new byte[1024]; Jk%'mEGE
int nRead; umqLKf=x!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) o; 6fvn
{ ~v^%ze
nStartPos += fileAccessI.write(b,0,nRead); Ri9Kr
//if(nThreadID == 1) id3)6}
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^}>zYt
} /*AJ+K._
-*rHB&e
b{zAJ`|#[n
Utility.log("Thread " + nThreadID + " is over!"); -3u@hp_
bDownOver = true; /rn"
//nPos = fileAccessI.write (b,0,nRead); Gg'<Q.H
} <>SR4
catch(Exception e){e.printStackTrace ();} Zlr{L]c
} Sb'N];
} ULV)0SB
G`9cd\^
\I'f3
//打印回应的头信息 +SAk:3.#CV
public void logResponseHead(HttpURLConnection con) ~*jsB=XM/
{ @gH(/pFX
for(int i=1;;i++) @X3 gBGY)
{ 2f`WDL
String header=con.getHeaderFieldKey(i); @][ a8:Y9I
if(header!=null) "xL;(Fqu
//responseHeaders.put(header,httpConnection.getHeaderField(header)); f37ji
Utility.log(header+" : "+con.getHeaderField(header)); 20$F$YYuk
else c*Eok?O
break; @47[vhE
} )>-77\
} J'I1,5(
}Q47_]5
e$ThSh\+(
public void splitterStop() tx2Vyu
{ dDsjPM;2
bStop = true; mrK,Ql
} i_[^s:*T
?SB[lbU
$&ex\_W
} sI^@A=.@
$,8CH)w
Y1#-^,qg
/* c-[Q,c
**FileAccess.java aQl?d<|+lk
*//文件访问(定位，写) MZ;"J82p
package NetFox; ,Wz[tYL*
import java.io.*; 6U;Jg_zS
9@$tiDV
fBHkLRFH
public class FileAccessI implements Serializable{ = 4BLc
73&]En
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 $ /}:P
RandomAccessFile oSavedFile; (eCF>Wh^m
long nPos; 9 Q0#We*
_F}IF9{?G
_#/!s]$d#
public FileAccessI() throws IOException +^/Nil
{ R88(dEK
this("",0); ,maAw}=
} "[%;B0J
ZAI1p+
2neF<H?^o
public FileAccessI(String sName,long nPos) throws IOException >P<k[vF
{ Ymwx(Pm
oSavedFile = new RandomAccessFile(sName,"rw"); Sf+(1_^`t
this.nPos = nPos; zF[3%qZE:T
oSavedFile.seek(nPos); 4]Un=?)I
} Paae-EmC
U@o2gjGN
OVDMC4K2z!
public synchronized int write(byte[] b,int nStart,int nLen) :6 Hxxh
{ o8~f
int n = -1; I ybl;u
try{ &*jxI[
oSavedFile.write(b,nStart,nLen); dAu^{1+2
n = nLen; Q\&AlV
} ki[;ZmQqY
catch(IOException e) ""25ay
{ w,M1`RsK
e.printStackTrace (); c7FfI"7HR
} ]7#^])>
W+#}~2&Dv
|%M{kA-
return n; U6/m_`nc
} hW0,5>[7%
kr/1Dsr4
C$N4
} A^T~@AO
"<cB73tY
+XU$GSw3(
/* #Qtg\X
**SiteInfoBean.java TS\A`{^T
*/ /o<}]]YBF
package NetFox; FT|/WZR
>.!5M L\
S7Iu?R_I
public class SiteInfoBean { ~aauW?
u7WTSL%
?1-n\ka
private String sSiteURL; //Site's URL Mm>zpB`qP
private String sFilePath; //Saved File's Path zVc7q7E
private String sFileName; //Saved File's Name W(u6J#2
private int nSplitter; //Count of Splited Downloading File `&|l;zsS
`>`K7-H
4y]:Gqz~
public SiteInfoBean() 'b=eC
{//nSplitter的缺省值为5 <tu[cA>
//default value of nSplitter is 5 '?vgp
this("","","",5); T>%uRK$
} 0%A(dJA6
Qq;m"M/
:oon}_MdRd
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) M0;t%*1
{ q/rHHuY}
sSiteURL= sURL; #o;CmB
sFilePath = sPath; q[y,J
sFileName = sName; s0`|G|.}
this.nSplitter = nSpiltter; ={mPg+Ei'
(IoPU+1b
y:hCBgc;`c
} 7{kpx$:_
QigoRB!z#9
lH,]ZA./
public String getSSiteURL() +}`O^#<qLX
{ xu_XX#9?b
return sSiteURL; U'h[{ek
} )L(d$N=Bd
vs'L1$L'c
7=QC+XSO
public void setSSiteURL(String value) V\rIN}7
{ MoKXl?B<
sSiteURL = value; ~ ];6hxv
} Q#J>vwi=
>F\rBc&
XTi0,e]5{u
public String getSFilePath() $3]E8t
{ "zeJ4f
return sFilePath; {-v\&w
} >jrz;r
Vhbj.eX.)
+EiUAs~H
public void setSFilePath(String value) [:R P9r}
{ }TX'Z?Lq
sFilePath = value; D|Ihe%w-
} <R`,zE@t'(
P/gb+V=g!
y_7XYT!w
public String getSFileName() \\R*V'e!
{ 0oi5]f6g?8
return sFileName; \@PUljU]
} Ng_rb KXC#
.X<"pd*@e
-MHX1`P:Sn
public void setSFileName(String value) ]/VIff
{ S]K6qY
sFileName = value; X_tW#`
} o+)LcoPu
(;Q <@PZg
&6|^~(P?
public int getNSplitter() {HRxyAI!
{ A^r [_dyZ
return nSplitter; s=y9!rr
} Eip~~2
sNk>0 X[
eFXi )tl
public void setNSplitter(int nCount) HDW\S#
{ 1:;&wf
nSplitter = nCount; LnRi+n[@7
} A]SB c2
} !7NzW7j
xBI"{nGoN
E~Up\f
/* aIt 0;D
**Utility.java Am=PUQF$
*/ P#2TM
package NetFox; #Mem2cz
1:{O RX[;
jXDzjt94J
public class Utility { Uhx2 _
RJ@e5A6_
|_xiG~
public Utility() "w|k\1D
{ Ppb2"Ik
/wxxcq
.IAHy)li"
} LWb}) #E
CQuvbAo
//线程睡眠 RoM*Qjw
public static void sleep(int nSecond) wmcp`8w.
{ \$HB~u%dr
try{ !{~7)iq
Thread.sleep(nSecond); l& ^B
} @n;YF5
catch(Exception e) 1d@^,7MF-
{ J>|:T
e.printStackTrace (); f?<M3P
} $E~Lu$|
} CL}I:/zRB
n$![b_)*
//日志 DwrCysIK
public static void log(String sMsg) 'm!11Phe
{ x]J-q5
System.err.println(sMsg); &\]f!'jV
} \=G Xe.}4d
~z1KD)^
wsGq>F~
public static void log(int sMsg) NMY!-Kv 5
{ &qI5*aQ8T
System.err.println(sMsg); oJp_c
} mlw BATi
} $XU$?_O
V_d%g<n4
UCj#t!Mw
/* Dp6"I!L<|
**TestMethod.java 5~R{,]52
*/ S| -{wC%
package NetFox; w>q_8V_K
]aW.b_7<9
[MXXY
public class TestMethod { ?QIQ,?.
<sFf'W_3{
yExyx?j.
public TestMethod() z` ?xS
{ ///xx/weblogic60b2_win.exe ~V- o{IA
try{ vAhO!5]>\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +#db_k
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); r`g;k&"a
SiteFileFetch fileFetch = new SiteFileFetch(bean); z4fK{S
fileFetch.start(); ]:#$6D"
} ds[Z=_Ll
catch(Exception e){e.printStackTrace ();} kuud0VWJ
adE0oXQH"
IlL
} .&Gtw _
qmyZbo|8&
@dKf]&h%%
public static void main(String[] args) Cwa0!y5%
{ ziGL4c0p
new TestMethod(); l45F*v]^
} i&Cqw~.H
} tJ_@AcF
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