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)); l&sO?P[ /
} Xf_tj:eO~
for(int i=0;i<nEndPos.length-1;i++) 5-5(`OZ{'
{ 1xdESorX(
nEndPos = nStartPos[i+1]; _IKP{WNB
} E"1;i
nEndPos[nEndPos.length-1] = nFileLength; 9MtJo.A
} S7NnC4)=-f
} Bx}0E
h>^jq{yu
.xz,pn}
//启动子线程 Xq^y<[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; N]s7/s
for(int i=0;i<nStartPos.length;i++) $|cp;~ 1
{ &Rl3y\ r
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K!D_PxV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;vv!qBl|@
nStartPos,nEndPos,i); \,%o>M'
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8/>wgY
fileSplitterFetch.start(); gLxT6v5wk.
} *L4]\wf
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _czbUl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); O^R:_vb3I
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]~ #+b>
nEndPos = " + nFileLength); 61+pryW%g
// fileSplitterFetch[nPos.length-1].start(); K*_{Rs0P
_> |R-vQ8
V:F+HMBk
//等待子线程结束 Ef_F#X0#
//int count = 0; L=$?q/=-
//是否结束while循环 -M1~iOb
boolean breakWhile = false; c6Yf"~TD0
csFJ5
1IF'>*
while(!bStop) CDnR
{ J+cAS/MYX
write_nPos(); {Ukc D+.Y
Utility.sleep(500); }[KDE{,V
breakWhile = true; 6& &}P79
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l)i&ATvCE
for(int i=0;i<nStartPos.length;i++) Q/3tg
{ *_{l
if(!fileSplitterFetch.bDownOver) |>IUtUg\
{ 0?6If+AC
breakWhile = false; :?$Sb8OuIL
break; oc3dd"8}@
} [DotS\p!z
} u>t|X}JH
if(breakWhile) @`IXu$Wm(
break; '!+P{
gI^L 9jE7
(DG@<K,6
//count++; \f /!
//if(count>4) M|[@znzR<
// siteStop(); h+B'_`(
} \8>
0\EpH[m}-
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System.err.println("文件下载结束！"); wuBlFUSg
} z<yNG/M1>U
catch(Exception e){e.printStackTrace ();} *w'q
} Q3NPwM
wr3_Bf3]
xs2,t*
//获得文件长度 j[m_qohd7
public long getFileSize() IDGQIg
{ |5}rX!wS4
int nFileLength = -1; wO2V%v^bp
try{ |<j,Tr1[
URL url = new URL(siteInfoBean.getSSiteURL()); 08Pt(kzNA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H-/; l54E
httpConnection.setRequestProperty("User-Agent","NetFox"); 6m, KL5>W
Ism^hyL
S+) l[0
int responseCode=httpConnection.getResponseCode(); YM#
if(responseCode>=400) Qq,i
{ 6?1s`{yy
processErrorCode(responseCode); l)tTg+:
return -2; //-2 represent access is error 9*}iBs
} &\J?[>EJ.
V-D}U$fw
9SRfjS{7
String sHeader; u(V
[K/O5_
NCowt|#t
for(int i=1;;i++) YVQ_tCC_!
{ la G$v-r
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); TIcd _>TW
//Utility.log(in.readLine()); ZQ,fm`y\
sHeader=httpConnection.getHeaderFieldKey(i); #dva0%-1
if(sHeader!=null) /<3;0~#){
{ |eHwp
if(sHeader.equals("Content-Length")) g9yaNelDh)
{ 0[n c7)sW
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); JCcN>DtP
break; Hv8SYQ|
} ,s1&O`
} $$haVY&
else zAeGkP~K
break; 9">zdFC'
} fOa6,
} kZV^F*7
catch(IOException e){e.printStackTrace ();} |?OdV<5C
catch(Exception e){e.printStackTrace ();} fH{9]TU_:
Zi 2o
1%$d D2
Utility.log(nFileLength); OOEV-=
v-P8WFjca
89LpklD
return nFileLength; ]]el|
} E S#rs="
$x?NNS_ "J
?8 SK\{9r6
//保存下载信息（文件指针位置） AuoxZ?V
private void write_nPos() DJmoW
{ ayV6m
try{ >;&Gz-lm
output = new DataOutputStream(new FileOutputStream(tmpFile)); |HrM_h<X
output.writeInt(nStartPos.length); ;EgzC^2e
for(int i=0;i<nStartPos.length;i++) 6OfdD.y
{ t9G}Yd[T
// output.writeLong(nPos); kP7a:(P_g
output.writeLong(fileSplitterFetch.nStartPos); 7cIC&(h5
output.writeLong(fileSplitterFetch.nEndPos); iLF^%!:X%
} uY.=4l
output.close(); v#RW{kI
} 285_|!.Y
catch(IOException e){e.printStackTrace ();} w- UKMW9"
catch(Exception e){e.printStackTrace ();} /h/6&R0l
} 1|o$X
sCVI 2S!L
;*y|8od B
//读取保存的下载信息（文件指针位置） RXGHD19]
private void read_nPos() 6!ZVd#OM%
{ \.c]kG>k-
try{ M6J/mOVx5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); zL9VR;q
int nCount = input.readInt(); ~}h^38
nStartPos = new long[nCount]; ~_'0]P\
nEndPos = new long[nCount]; Y.q>EUSH
for(int i=0;i<nStartPos.length;i++) KR&s?
{ dSwm|kIa
nStartPos = input.readLong(); M{]e5+
nEndPos = input.readLong(); 2< p{z
} I^WIa"u_
input.close(); fs&,w
} ]\OWZ{T'j
catch(IOException e){e.printStackTrace ();} W@l+ciZ_
catch(Exception e){e.printStackTrace ();} 3@&bxYXm
} o>2e!7
c\M#5+1j
6G'<[gL j
private void processErrorCode(int nErrorCode) {]=v]O|,
{ Q4X7Iu:
System.err.println("Error Code : " + nErrorCode); Xad*Iulj
} HeCcF+
XdcG0D^
9ftN8Svw
//停止文件下载 mV<i JZh
public void siteStop() , 7Xqte
{ *9J1$Wa
bStop = true; hL0]R,t;'
for(int i=0;i<nStartPos.length;i++) ,E&Bn8L~O
fileSplitterFetch.splitterStop(); u,fA!
prZ55MS.
#Rc5c+/(
} eK9TAW
} -n$ewV
//负责部分文件的抓取 CD}Ns
**FileSplitterFetch.java Yb}w;F8(
*/ 3wZ(+<4i
package NetFox; i|%5
Kh)FyV
BBvZeG $Y
import java.io.*; L!gDFZr
import java.net.*; jPnO@H1
z!:'V]
y?>#t^
public class FileSplitterFetch extends Thread { 27>a#vCT
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=N_,l'U\^
String sURL; //File URL 9RxO7K
long nStartPos; //File Snippet Start Position "IG+V:{ou
long nEndPos; //File Snippet End Position =O,JAR"ug
int nThreadID; //Thread's ID uArR\k(
boolean bDownOver = false; //Downing is over hY+R'9
boolean bStop = false; //Stop identical _9NVE|c;
FileAccessI fileAccessI = null; //File Access interface H>.B99vp
>dk9f}7-
('t kZt%8
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >!}`%pk(
{ QsOhz
this.sURL = sURL; =Ey`M#t;
this.nStartPos = nStart; n>P!u71
this.nEndPos = nEnd; Noh?^@T`Ov
nThreadID = id; vBNZ<L\|a
fileAccessI = new FileAccessI(sName,nStartPos);//定位 x5OC;OQc
} 6 mO"
|) Pi6Y
t8&q9$
public void run() Jf)3< ~G
{ :tM?%=Q
while(nStartPos < nEndPos && !bStop) b{RqwV5P
{ pcH<gF(k
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yG&2UqX
try{ 8Mu;U3cIW
URL url = new URL(sURL); YsP/p-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }>&KUl
httpConnection.setRequestProperty("User-Agent","NetFox"); nJJs%@y
String sProperty = "bytes="+nStartPos+"-"; pUCK-rL
httpConnection.setRequestProperty("RANGE",sProperty); (KTnJZ
Utility.log(sProperty); ioV_oR9I
<C<`J{X0
iq6a|XGi
InputStream input = httpConnection.getInputStream(); xMI+5b8
//logResponseHead(httpConnection); 0Q~@F3N-\>
O"*`'D|hK
ni6r{eSQ
byte[] b = new byte[1024]; 2yKz-"E
int nRead; z<pJYpxH
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \cQ .|S
{ R#(G%66
nStartPos += fileAccessI.write(b,0,nRead); %y"J8;U
//if(nThreadID == 1) vG Vd
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "+|L_iuNQ
} s&'BM~WI
!gH9ay
~O;y?]U
Utility.log("Thread " + nThreadID + " is over!"); hazq#J!
bDownOver = true; Pl+xH%U+?
//nPos = fileAccessI.write (b,0,nRead); 6:?rlh
} )"`!AerJ
catch(Exception e){e.printStackTrace ();} 4:mCXP,x
} |NrrTN?>
} 0xpx(T[
TfRGA(+#
^Y04qeRd
//打印回应的头信息 4_LQ?U>$
public void logResponseHead(HttpURLConnection con) #Qbl=o4
{ '#Dg8/r!
for(int i=1;;i++) 4/*H.Fl
{ ,P6=~q3k
String header=con.getHeaderFieldKey(i); 0oU=RbC
if(header!=null) Lw*]EG|?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )%Ru#}1X6
Utility.log(header+" : "+con.getHeaderField(header)); Cd]/
else GBP-V66
break; ._CP% R
} <7n]Ai@Y
} EO)%UrWnC
+.Bmkim
&uM^0eM
public void splitterStop() GXX+}=b7qO
{ .Q>!B?)
bStop = true; VC-;S7k
} (j&A",^^S
(/h5zCc/v
'v&}(
} vR>o}%`
z`$J_CjY
wJG$c-(\0
/* eW8[I'v_&
**FileAccess.java n56;m`IU
*//文件访问(定位，写) I*\^,ow
package NetFox; mlu 3K
import java.io.*; ~ 3T,&?r
&L4 q10-N
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public class FileAccessI implements Serializable{ ULBg{e?l8
UQT'6* !
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .q;ED`G
RandomAccessFile oSavedFile; Hl7:*]l7b
long nPos; |L:Cn J
zAScRg$:?
>V;,#5F_
public FileAccessI() throws IOException qv+R:YYOq
{ Bjj<\8^M
this("",0); Z=+03
} NZXjE$<Vr
Lz4ehWntO
cd.brM
public FileAccessI(String sName,long nPos) throws IOException .%xzT J=!
{ MZv\ C
oSavedFile = new RandomAccessFile(sName,"rw"); i$UQbd
this.nPos = nPos; HJhH-\{@
oSavedFile.seek(nPos); S>_27r{
} 1BTIJ Gw
9dKul,c
7#2j>G{?]v
public synchronized int write(byte[] b,int nStart,int nLen) ?Zcj}e.r
{ \pY^^ l*
int n = -1; -50AX1h31:
try{ ;Zut@z4\
oSavedFile.write(b,nStart,nLen); 'Ud|Ex@A9
n = nLen; 3/goCg
} >3D7tK(
catch(IOException e) d"THt}
{ Q9>U1]\
e.printStackTrace (); p1O6+hRio
} V@ :20m
+=3CL2{An
9$l>\.6
return n; raB+,Oi$G
} 0[a}n6XTk
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2x}6\t
} /c-nE3+rn
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}e{qW
/* K|^wc$
**SiteInfoBean.java xtfRrX^
*/ bEH de*q(
package NetFox; 8^yJqAXK
=@r--E
qfL-r,XS`F
public class SiteInfoBean { d*]Ew=^L
pyB~M9Bp/
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private String sSiteURL; //Site's URL d'HOpJE
private String sFilePath; //Saved File's Path |. C1|J'Z
private String sFileName; //Saved File's Name %|"Qi]c d
private int nSplitter; //Count of Splited Downloading File r%=[},JQ
_p}xZD\?,
zFhgE*5
public SiteInfoBean() KSqTY>%fnv
{//nSplitter的缺省值为5 2(#Ks's?
//default value of nSplitter is 5 Dy9\O77>
this("","","",5); <8o(CA\
} :nGMtF
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) eti`O
{ WS0JS'
sSiteURL= sURL; TT}]wZ
sFilePath = sPath; p2pAvlNoF
sFileName = sName; e>H:/24
this.nSplitter = nSpiltter; QGPw2Q
;4~U,+Av
|:q/Dt@
} $aP(|!g
.YcN S%
vzR=>0#
public String getSSiteURL() PEXq:TA
{ %5B%KCCN
return sSiteURL; j4.&l3
} Np,2j KF(
=,/D/v$m'2
#$1$T
public void setSSiteURL(String value) 4E3g,%9u
{ 9`Q@'(m
sSiteURL = value; IB$7`7
} jj&s}_75
tJZc/]%`H
d/U."V}
public String getSFilePath() ;st\I
{ u?0d[mC
return sFilePath; ]> G&jd7
} igkz2SI
M7dU@Ag
i@$*Csj\9*
public void setSFilePath(String value) LI W*4r!
{ iS: #o>
sFilePath = value; P%>?[9!Nt
} v,1F--v
$|<m9CW
>S#ul?
public String getSFileName() (4+1lOd
{ a39hP*
return sFileName; \V%_hl
} 's%q
CEtR[Cu
0D[@u3W
public void setSFileName(String value) By((,QpB
{ `/:cfP\
sFileName = value; Ot9V< D6h
} f(:1yl\a
3N4.$#>#9@
([k7hUP
public int getNSplitter() 3LK%1+)4
{ N6/T#UVns
return nSplitter; $99R|^
} ?d-70pm
JLm @Ag
"4 k-dj
public void setNSplitter(int nCount) ?]!vRmZ;
{ ^Kq|ID AP
nSplitter = nCount; A WJWtUa
} {d!Y3+I%G
} IgX4.]W5
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}T(z4P3
/* ;VzMU ;j
**Utility.java +Ui_ O
*/ |nxdB&1n
package NetFox; 5 2Hqu>
v\A.Tyy
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public class Utility { =_-C%<4
j\2[H^
n[" 9|
public Utility() []}N
{ y-+G wa3
@$U e$
vDE |sT
} P Jo
Sb"2Im>
//线程睡眠 &Ocu#Cb
public static void sleep(int nSecond) J!p<oW)a!
{ 0HibY[_PbD
try{ BQNp$]5s
Thread.sleep(nSecond); S/Oxr%H
} \<65??P
catch(Exception e) H5M#q6`H6
{ 3H8Al
e.printStackTrace (); <DmTj$
} ^.HWkS`e
} <GZhH:
.6T4z7I
//日志 8pe0$r`b
public static void log(String sMsg) !Q)3-u
{ m&El)
System.err.println(sMsg); 3|eUy_d3
} 9g@NcJ]
-Ktwo_V*
z7=fDe -
public static void log(int sMsg) >t#\&|9I
{ p;->hn~D'5
System.err.println(sMsg); 5gK~('9'?1
} Eo=HNe
} o#{#r@,i
kL;t8{n
{ymb\$f
/* r{ @ `o@q
**TestMethod.java pxplWP,
*/ HdCk!Fv
package NetFox; !0jq6[&
n;OHH{E{
A{`]&K1u
public class TestMethod { 6>B \|
K&S@F!#g
S0xIvzS
public TestMethod() 'Y)/~\FI
{ ///xx/weblogic60b2_win.exe h48 bb.p2
try{ E .;io*0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); F#1kZ@nq
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Oz>io\P94
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^!uO(B&
fileFetch.start(); 2"M_sL
} t2.juoI(
catch(Exception e){e.printStackTrace ();} pqfT\Kb>
NG)7G
78w4IICk
} -\,VGudM}
gKQ@!UU8
3"tg+DncC
public static void main(String[] args) 3- )kwy6L
{ 9::YR;NY
new TestMethod(); { _X#fq0}
} vnZ/tF
} (`mOB6j
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