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)); +lJG(Qd
} p+l!6
for(int i=0;i<nEndPos.length-1;i++) cU0s p
{ 9[1`jtm
nEndPos = nStartPos[i+1]; 3mYiQ2
} gfsI6/Y
nEndPos[nEndPos.length-1] = nFileLength; EG0WoUX|
} u1t%(_h
} $SM#< @
$tz;<M7B
)_{dWf1
//启动子线程 $}lbT15a
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; t>1Z\lE\"
for(int i=0;i<nStartPos.length;i++) XD|E=s
{ x;-. ZVF
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?g?L3vRK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )\sc83L
nStartPos,nEndPos,i); hy}8Aji&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kjEEuEv
fileSplitterFetch.start(); 5nv<^>[J
} |_o=^?z'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qP{/[uj[K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7nHF@Y|*"
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .%.9n\b
nEndPos = " + nFileLength); ,stN
// fileSplitterFetch[nPos.length-1].start(); wSb1"a
3= xhoRX
S>.SSXlM
//等待子线程结束 Q@ 2i~Qo[
//int count = 0; (Q%'N3gk
//是否结束while循环 ~\=1'D^6CK
boolean breakWhile = false; 7:9.&W/KE
L!=4N!j
,S'p%g
while(!bStop) XEn*?.e
{ _{R=B8Zz\
write_nPos(); '&.#
Utility.sleep(500); :>D[n1v
breakWhile = true; #[zI5)Meh
t'BLVCu
(7XCA,KTGI
for(int i=0;i<nStartPos.length;i++) W5?yy>S6N
{ Vy*:ne
if(!fileSplitterFetch.bDownOver) Xv<B1
{ a["2VY6Eq@
breakWhile = false; vJ\pR~?
break; N` aF{3[
} a;QMAd!
} rA2g&
if(breakWhile) 6b%WHLUeT
break; ^xh}I5
.mDM[e@'
rFaF Bd
//count++; 9so6WIWc
//if(count>4) <Ard7UT
// siteStop(); `D`sr[3n
} [[>wB[w
I4i2+ *l}
*g y{]
System.err.println("文件下载结束！"); $ "E).j
} 8wVY0oRnU
catch(Exception e){e.printStackTrace ();} uHAT#\m:
} xEf'Bmebk
VYt!U
)Psb>'X
//获得文件长度 ]l'Y'z,}
public long getFileSize() K$M^gh0
{ qw@puw@D
int nFileLength = -1; U+)xu>I
try{ 3dht!7/
URL url = new URL(siteInfoBean.getSSiteURL()); w"OP8KA:^T
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L3G \
httpConnection.setRequestProperty("User-Agent","NetFox"); M9y<t'
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wD68tG$
int responseCode=httpConnection.getResponseCode(); \[gReaI
if(responseCode>=400) slg ]#Dy
{ HPb]Zj
processErrorCode(responseCode); ,$'])A?$
return -2; //-2 represent access is error GP&vLt51
} NZ/yBOD(
J9\a{c;.
9cEv&3
String sHeader; $aN-Y?U%
N@Y ljz|
TF 'U
for(int i=1;;i++) <$F\Nk|x
{ yY[<0|o u
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); JJ{9U(`_y6
//Utility.log(in.readLine()); (FJ9-K0b{n
sHeader=httpConnection.getHeaderFieldKey(i); L=q+|j1>
if(sHeader!=null) p98~&\QT
{ 4hAl-8~Q6
if(sHeader.equals("Content-Length")) O!Oumw,$
{ :um|nRwy9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); X{we/'>
break; 6B@CurgB
} YO}1(m
} wjh=Q
else _)]+hUwY
break; SB5&A_tr
} td4[[ /
} abJ" [
catch(IOException e){e.printStackTrace ();} AJSx%?h:6
catch(Exception e){e.printStackTrace ();} Qb)C[5a}
HsnLm67'
br0++}vwL
Utility.log(nFileLength); 7\f\!e <
?Y:8eD"*
zN{K5<7o
return nFileLength; \0mb 3Q'
} ~(pmLZ<GW}
lY{FSGp
(tCUlX2
//保存下载信息（文件指针位置） vfl5Mx4
private void write_nPos() jCrpL~tWT
{ H|ER
try{ srYJp^sC
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^bc;[x&N
output.writeInt(nStartPos.length); c%[#~;E
for(int i=0;i<nStartPos.length;i++) KN?6;G{
{ ;zYqsS
// output.writeLong(nPos); a)S+8uU
output.writeLong(fileSplitterFetch.nStartPos); )ZBY* lk9
output.writeLong(fileSplitterFetch.nEndPos); YKE46q;J
} nK$X[KrV'
output.close(); B*~5)}1op
} NvHJ3>"%
catch(IOException e){e.printStackTrace ();} BWrv%7
catch(Exception e){e.printStackTrace ();} !2z?YZhu
} : C b&v07
\mw(cM#:
-0_d/'d
//读取保存的下载信息（文件指针位置） IBQ@{QB
private void read_nPos() +&Hr4@pgW
{ jMbC Y07v
try{ 6gT5O]]#o
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Pl<;[cB
int nCount = input.readInt(); u{FDdR9<
nStartPos = new long[nCount]; E[O<S B I
nEndPos = new long[nCount]; n @?4b8"
for(int i=0;i<nStartPos.length;i++) _:X|.W
{ p|Q*5TO
nStartPos = input.readLong(); "Vr[4&`
nEndPos = input.readLong(); o/C\d$i'
} p_UlK8rb
input.close(); V\})3i8
} _[Vf547vS
catch(IOException e){e.printStackTrace ();} H)aQ3T4N5
catch(Exception e){e.printStackTrace ();} sTOa
} i~3u>CT
3d-%>?-ee
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private void processErrorCode(int nErrorCode) 2_ :n
{ UjOB98Du
System.err.println("Error Code : " + nErrorCode); Y!WG)u5
} +3a?`Z
:>aQ~1f>]
k{VE1@
//停止文件下载 '{[5M!B
public void siteStop() Ja SI^go
{ .`7cBsXH
bStop = true; ,ZQZ}`x(
for(int i=0;i<nStartPos.length;i++) *26334B.R
fileSplitterFetch.splitterStop(); P_c,BlfGMH
gtYAHi
VR
} 'kYwz;gp
} V97,1`
//负责部分文件的抓取 gr-fXZO
**FileSplitterFetch.java /B5-Fx7j3
*/ 6G}+gqbX
package NetFox; JT9N!CGZ
lc_E!"1
hoT/KWD,
import java.io.*; x+]!m/
import java.net.*; y7S4d~&
XyMG.r-,
goJ|oi
public class FileSplitterFetch extends Thread { j F-v%?
tTN?r8
+fx8muz:y
String sURL; //File URL zZiJ 9 e
long nStartPos; //File Snippet Start Position q~L^au8
long nEndPos; //File Snippet End Position *cTO7$\[
int nThreadID; //Thread's ID 2Bk$ lx7
boolean bDownOver = false; //Downing is over ?0_7?yTR/
boolean bStop = false; //Stop identical V:/7f*n7
FileAccessI fileAccessI = null; //File Access interface /%A;mlf{
tA$)cg+.
cst}Ibfi
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException N$TL;T>
{ =`Y.=RL+'n
this.sURL = sURL; XhdSFxW}
this.nStartPos = nStart; Xnuzr"4u
this.nEndPos = nEnd; tRw@U4=y
nThreadID = id; 'cNKjL;
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9_fePS|Z4
} okq[ o90
O+=vEp(
qn"D#K'&(
public void run() {FN;'Uc
{ }j1!j&&
while(nStartPos < nEndPos && !bStop) k>E`s<3
{ 5cK@WE:
l{ex?
n:U>Fj>q
try{ hNXBVIL<&
URL url = new URL(sURL); qQxz(}REu9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); AGYm';z3
httpConnection.setRequestProperty("User-Agent","NetFox"); i`)!X:j
String sProperty = "bytes="+nStartPos+"-"; 2JmZ{
httpConnection.setRequestProperty("RANGE",sProperty); U-0#0}_
Utility.log(sProperty); yBLUNIr
^*R(!P^
Lt#'W
InputStream input = httpConnection.getInputStream(); v&g0ta@
//logResponseHead(httpConnection); 5)zn:$cz
.Qt4&B
)[&_scSa
byte[] b = new byte[1024]; ,J mbqOV?!
int nRead; ?p[O%_Xf
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R*1kR|*_)
{ 1u]P4Gf=
nStartPos += fileAccessI.write(b,0,nRead); vMSW$Bx ;
//if(nThreadID == 1) Oajv^H,Em
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L6 6-LMkH
} ^T4Ay=~{
b'x$2K;E
H L<s@kEZ
Utility.log("Thread " + nThreadID + " is over!"); S"snB/
bDownOver = true; iO!6}yJ*V
//nPos = fileAccessI.write (b,0,nRead); P\~{3U
} )_jSG5k
catch(Exception e){e.printStackTrace ();} t~K%.|'0
} IGj`_a
} PfW|77
"oc$
}4%/pOi:f
//打印回应的头信息 FQeYx-7
public void logResponseHead(HttpURLConnection con) O>DNC-m)i{
{ fW0$s`
for(int i=1;;i++) Lx|',6S
{ #j@OLvXh
String header=con.getHeaderFieldKey(i); !ZtSbOC'
if(header!=null) ?~ULIO'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Q]JX`HgPaU
Utility.log(header+" : "+con.getHeaderField(header)); e`UQz$4!
else <"&'>?8j
break; 3" Vd==oK~
} aSaAC7sFk
} rjojG59U>
:iY$82wQ
(wt+`_6
public void splitterStop() XYbyOM VI
{ 7 Yv!N
bStop = true; wODvc9p}]
} ahIE;Y\j'
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H/cTJ9zz
} Q .RO
"G?9b
CJw$j`k
/* L`K;IV%;
**FileAccess.java VQ |^
*//文件访问(定位，写) p!"(s/=
package NetFox; 9R]](g#
import java.io.*; G!-J$@P
m/${8
3o8\/-*<
public class FileAccessI implements Serializable{ Y)p4]>lT+8
!*a[jhx
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 hLuJWjCV
RandomAccessFile oSavedFile; F1u)i
long nPos; #\FT EY!
q.oLmX
M9"Sgb`g
public FileAccessI() throws IOException RV!<?[
{ kojG-M
this("",0); r,'O).7
} /7p>7q9g
*TnzkNN_,
nxRwWj57
public FileAccessI(String sName,long nPos) throws IOException G=$}5; t
{ 3V-6)V{KaE
oSavedFile = new RandomAccessFile(sName,"rw"); cf*zejbw
this.nPos = nPos; 9)ea.Gu
oSavedFile.seek(nPos); zl)&U=4l
} YN#XmX%
:WX0,-Gn
!C`20,U
public synchronized int write(byte[] b,int nStart,int nLen) jH0Bo;
{ /yK"t<p
int n = -1; ?`. XK}
try{ f)Y
oSavedFile.write(b,nStart,nLen); A'g,:8Ou
n = nLen; C_-E4I Z)
} ?aJ6ug
catch(IOException e) xwLy|&
{ IK?]PmN4}
e.printStackTrace (); plku-O;]
} dQ6GhS~
lPS*-p#IZ
&7][@v
return n; /co%:}ln
} j`9Nwa
BTs0o&}e
"_)|8|gN
} #JS`e_3Rr
SsRVd^=;x
JN^bo(kb
/* k/^g*
**SiteInfoBean.java _80ns&q
*/ vf_OQ4'G,
package NetFox; t?.\|2
u\5g3BH
d$Em\*C
public class SiteInfoBean { {G.jB/
Z:^3Fm->+
^srs$ w]
private String sSiteURL; //Site's URL Mdm0g
private String sFilePath; //Saved File's Path '>]&rb09|
private String sFileName; //Saved File's Name `]&*`9IK{
private int nSplitter; //Count of Splited Downloading File uQ1jwYK`7
-$L(y@%X^
%yhI;M^
public SiteInfoBean() >;}]pI0T
{//nSplitter的缺省值为5 K P6PQgc
//default value of nSplitter is 5 LaT8l?q q
this("","","",5); v>:=w|.HC
} tQf!|]#J
j@SYXKL~
4tnjXP8
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;_p fwa4
{ \CwtX(6.
sSiteURL= sURL; j`Nh7+qs
sFilePath = sPath; ITQ9(W Un
sFileName = sName; kYtHX~@
this.nSplitter = nSpiltter; ,4yG(O$)
w>vmF cp
fO+UHSC
} N1s.3`
u#!GMZJN
DUo0w f#D^
public String getSSiteURL() bN!u}DnN
{ p_gA/. v=
return sSiteURL; PS/W h
} -;<>tq'3`
d}VALjXHX!
Z?C4a}
public void setSSiteURL(String value) w Oj88J)
{ >\&= [C
sSiteURL = value; NkoofhZ
} W/a,.M
7y>(H<^>
pMDH
public String getSFilePath() {70Ou}*
{ )Oo2<:"
return sFilePath; D2Vv\f
} pd7O`.3
t#{x?cF
*{Yi}d@h(
public void setSFilePath(String value) R@OSqEnr
{ PJ0Jjoh"Y
sFilePath = value; 6."PS4}:
} EqoASu
g@}6N.]#
S_j1=6#^
public String getSFileName() IY03"
{ 9D%qXU
return sFileName; q$|0)}
} L1rAT
Pwg/Vhfh
:+<t2^)rD
public void setSFileName(String value) PRZ8X{h
{ B3eNFS
sFileName = value; m}rh|x/?
} X;(oz]tr$
3]!h{_:u
YK7\D:
public int getNSplitter() @OY1`EuO
{ V*>73I
return nSplitter; {dZ!I
} t(wZiK}
7 TmK
VZt;P%1;h
public void setNSplitter(int nCount) |$Qp0vOA}
{ uvR0TIF4
nSplitter = nCount; i]LU4y%'
} :&qC<UD
} h)7v1,;w'
>eEnQ}Y
)CFk`57U
/* LgO i3
**Utility.java `S5>0r5[
*/ ?rAi=w&c
package NetFox; a^%8QJW
]"C| qR*
cO8`J&EK
public class Utility { 3L?WTS6(u
V[4(~,9
BN_!Y)Fl
public Utility() IES41y<
{ 1d=0q?nH
{bW"~_6}
Q-M rH
} "9)1K!tH
37J\i ]
//线程睡眠 H<v c\r
public static void sleep(int nSecond) @QvfN>T
{ (qNco8QKu3
try{ zNNzsT8na
Thread.sleep(nSecond); &*X3ch
} RmcYaj^=
catch(Exception e) m]bL)]Z
{ l :f9Ih
e.printStackTrace (); ztRWIkI q
} e@='Q H
} QBg}2.
NvXj6U*%
//日志 U;x99Go:
public static void log(String sMsg) !O 0ZD4/{4
{ `=_7I?
System.err.println(sMsg); NTXws4'D
} ^hQ:A4@q
FCsyKdM
DR.3 J`?K
public static void log(int sMsg) [V!^\g\6
{ TKj/6Jz|
System.err.println(sMsg); u!=]zW%
} -~QlHp&SY
} P^'>dOI0w
O+CF/ipX/
v*vub#wP
/* YHwVj?6W
**TestMethod.java 5Ws:Ei{R
*/ F9>(W#aC
package NetFox; $i1>?pb3
RW|UQY#
<MI$Nl
public class TestMethod { @LwVmR |{
OF<[Nh\.
mvW^P`nB
public TestMethod() Mt7X<?GZm
{ ///xx/weblogic60b2_win.exe 'ugR!o1
try{ B=o#LL
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !VJT"Ds_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); QrrZF.
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;&7qw69k
fileFetch.start(); jS5t?0
} JsAb q
catch(Exception e){e.printStackTrace ();} @n~ND).
bOnukbJ
YV2pERl
} qB`0^V
\k$]GK-
v]d?6g
public static void main(String[] args) $AL|d[[T[
{ A-@-?AR
new TestMethod(); ;1(qGy4
} 0X}w[^f
} DI"dY ug#
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