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)); +}1h
} w{TZN{Y
for(int i=0;i<nEndPos.length-1;i++) .\)`Xj[?
{ Ya~*e;CW2
nEndPos = nStartPos[i+1]; F/O5Z?C?
} &BTgISYi
nEndPos[nEndPos.length-1] = nFileLength; qV]p\/a.
} E0HXB1"
} }9=X*'BO
oE/g)m%
<5@VFRjc
//启动子线程 @ByD=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; RBuerap
for(int i=0;i<nStartPos.length;i++) B\^myg4
{ )c*NS7D~f
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T<XGG_NOl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8k[=$Ro
nStartPos,nEndPos,i); p6S{OUiG
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |y%pJdPk=
fileSplitterFetch.start(); GO&~)Vh&7
} .kwz$b+h
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >I*)0tE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ={g.Fn(_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", t"# .I?S0
nEndPos = " + nFileLength); w1;:B%!H
// fileSplitterFetch[nPos.length-1].start(); *~Y$8!ad
z3-A2#c
j}s<Pn%4
//等待子线程结束 : ;l9to
//int count = 0; yBKEw(1
//是否结束while循环 s|HpN
boolean breakWhile = false; ~V34j:
_L8|ZV./
z3Id8G&>
while(!bStop) =#=<%HPT
{ @kh:o\
write_nPos(); k]>1@t
Utility.sleep(500); WzinEo{f
breakWhile = true; "R<c
4C:-1gu7
l7T@<V
for(int i=0;i<nStartPos.length;i++) j(xVbUa
{ Budo9z_w
if(!fileSplitterFetch.bDownOver) I}^Q u0ub
{ r,cz yE/
breakWhile = false; xgp 6lO[
break; etw.l~y
} &[yW}uV<7
} 7=3'PfS
if(breakWhile) zjE|UK{
break; v79k{<Ln
S[zETRSG
<ztcCRov
//count++; \|@u)n_
//if(count>4) <Pn]{N
// siteStop(); LC>bZ!(i#
} e};\"^HH
p[LPi5
VZz>)Kz:
System.err.println("文件下载结束！"); @"h@4q/W
} !=)b2}e/>
catch(Exception e){e.printStackTrace ();} Qxb%P<`u
} f[ 'uka.U
3*(w=;y
pLdZB9oD]C
//获得文件长度 q9 SV<qg
public long getFileSize() ~7 w"$H8
{ aw\0\'}
int nFileLength = -1; )swu~Wb}U@
try{ 1XppC[))
URL url = new URL(siteInfoBean.getSSiteURL()); !+EE*-c1c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); E\Qm09Dj`<
httpConnection.setRequestProperty("User-Agent","NetFox"); n9H4~[JiC
ITssBB9
'g5 Gdn
int responseCode=httpConnection.getResponseCode(); UG !+&ii|
if(responseCode>=400) "L9yG:
{ xfzGixA
processErrorCode(responseCode); aam6R/4
return -2; //-2 represent access is error S"<"e\\}"_
} fW3awR{
~bD'QMk
L,\wB7t
String sHeader; b[/uSwvi
dje}CbZ
\+#>XDD
for(int i=1;;i++) {t%Jc~p{
{ fbrCl!%P
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); EEJ OJ<
//Utility.log(in.readLine()); 2kSN<jMr
sHeader=httpConnection.getHeaderFieldKey(i); 9aoGptgN
if(sHeader!=null) }lQ`ka
{ $S'~UbmYU
if(sHeader.equals("Content-Length")) w,x'FZD
{ P1_ZGeom*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); S x0QPX
break; 5H^"
} ExxD w_VGT
} Ri<'apl
else eEmuE H@X
break; JwNB)e D
} WV&grG|
} y#iQ
catch(IOException e){e.printStackTrace ();} uGz>AW8a3
catch(Exception e){e.printStackTrace ();} dWi:V7t+
[/Vi*Z
&YOks.k
Utility.log(nFileLength); 7#[8td
"CTK%be{q/
ym*oCfu=
return nFileLength; )|N_Q}
} 5fvY#6;
iXPe
0`Hr(J`F
//保存下载信息（文件指针位置） T$IwrTF@?
private void write_nPos() M"\j7(
{ f=--$o0U~
try{ +t7n6
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?,z/+/:
output.writeInt(nStartPos.length); _O;2.M%@
for(int i=0;i<nStartPos.length;i++) hdN[wC]
{ p*C|kEqk
// output.writeLong(nPos); vp4NH]fJ
output.writeLong(fileSplitterFetch.nStartPos); ^~DDl$NH
output.writeLong(fileSplitterFetch.nEndPos); #`o]{UfW
} 5H79-QLd
output.close(); = P@j*ix
} 5Z_7Sc
catch(IOException e){e.printStackTrace ();} `Kb"`}`_vm
catch(Exception e){e.printStackTrace ();} ] ^s,
} b^^ .$Gu
Q:^.Qs"IK
c]PG5f xf
//读取保存的下载信息（文件指针位置） TfnBPO
private void read_nPos() %f1>cO9[
{ .H#<yPty
try{ *-`-P
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [BZA1,
int nCount = input.readInt(); Ka/*Z4"
nStartPos = new long[nCount]; d1BE;9*/7
nEndPos = new long[nCount]; ~5]%+G
for(int i=0;i<nStartPos.length;i++) <,+nS%a
{ "pMx(
nStartPos = input.readLong(); hF^y4v|5
nEndPos = input.readLong(); tl"?AQcBR
} yOswqhz
input.close(); yFY:D2
} l|j}Ggen
catch(IOException e){e.printStackTrace ();} C3:CuoE X
catch(Exception e){e.printStackTrace ();} EWC{896,
} uA;vW\fHr
DkJ "#8Yl=
JU3to_Io
private void processErrorCode(int nErrorCode) 73kU\ux
{ 0WI@BSHnM
System.err.println("Error Code : " + nErrorCode); 11YpC;[o
} eufGU)M
b <z)4
h/pm$9A
//停止文件下载 >m+Fm=
public void siteStop() /C
{ D^)?*(
bStop = true; !]C=5~BBI
for(int i=0;i<nStartPos.length;i++) >e"vPW*[
fileSplitterFetch.splitterStop(); gT{WH67u
6-Id{mx
rsn^YC
} LTw.w:"J
} d;hv_h
//负责部分文件的抓取 s2`Qh9R
**FileSplitterFetch.java -*[:3%
*/ _lMSW6
package NetFox; D~b_nFD
!hjA
Ox%p"xuP,
import java.io.*; oM(8'{S=
import java.net.*; }l7@:ezZZ7
/i)>|U 4
N~|Z@pU"
public class FileSplitterFetch extends Thread { CmxQb,Uls
ybU_x
;~-M$a }4
String sURL; //File URL B+2EIaI
long nStartPos; //File Snippet Start Position wl/1~!
long nEndPos; //File Snippet End Position } /*U~!t
int nThreadID; //Thread's ID MqjdW
boolean bDownOver = false; //Downing is over L%HFsuIO-
boolean bStop = false; //Stop identical @p<tJR"M
FileAccessI fileAccessI = null; //File Access interface {Jc.49
Om_-#S
^v5<*uf%m
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException <Uc?#;%Y}
{ xi[\2g+
this.sURL = sURL; )F_nK f"a
this.nStartPos = nStart; u';9zk/$
this.nEndPos = nEnd; ./35_Vy/O
nThreadID = id; u*$]Bx
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =K<`nF0w
} F%IvgXt5
F R(k==pZ
hn=tSlte
public void run() v>/_U
{ B!1h"K5.($
while(nStartPos < nEndPos && !bStop) TW6F9}'f&
{ gC+?5_=<
C7FxV2
T^icoX=c4
try{ nc^DFP
URL url = new URL(sURL); +_1sFH`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :i>If:>g
httpConnection.setRequestProperty("User-Agent","NetFox"); hgK 4;R
String sProperty = "bytes="+nStartPos+"-"; =Q*x=}NH
httpConnection.setRequestProperty("RANGE",sProperty); ckYT69U
Utility.log(sProperty); .Ta(v3om%
)&j@={0
#%g>^i={ky
InputStream input = httpConnection.getInputStream(); G%ZP`
//logResponseHead(httpConnection); UM<!bNz`
nJ}@9v F/
H[RX~Xk2E
byte[] b = new byte[1024]; 0X:$ASocU
int nRead; Y@Ur}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +c$:#9$ |
{ _FxeZ4\
nStartPos += fileAccessI.write(b,0,nRead); e2yCWolmTS
//if(nThreadID == 1) :gn&wi
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {H*
} jG{OLF6 !
>f'aW
'+\t,>nRkl
Utility.log("Thread " + nThreadID + " is over!"); x~Dj2F]
bDownOver = true; JwQ/A[b
//nPos = fileAccessI.write (b,0,nRead); IGOEqUw*
} 82iFk`)T
catch(Exception e){e.printStackTrace ();} sYbmL`{
} p\R&vof*
} !Df>Q5~g
.C` YO2,
EbG&[v
//打印回应的头信息 @H8DGeM
public void logResponseHead(HttpURLConnection con) (K_{a+$[
{ 5z&>NI
for(int i=1;;i++) 6AdC
{ 1obajN
String header=con.getHeaderFieldKey(i); ~=Q^]y,
if(header!=null) ^YJ%^P
//responseHeaders.put(header,httpConnection.getHeaderField(header)); wXtp(YwlH
Utility.log(header+" : "+con.getHeaderField(header)); !;;7:!)P
else < 0YoZSNGj
break; f]_'icP
} hr!'
} {[3xi`0-
e/&^~ $h
E\ls- (,
public void splitterStop() 3m| C8:
{ THARr#1b};
bStop = true; VeSQq
} mVFo2^%v
BOWBD@y
u 7:Iv
} A"z9t#dv@
74 &q2g{
+D2I~hC0'
/* W>5[_d
**FileAccess.java TbaZFLr
*//文件访问(定位，写) s94*uZ(C/
package NetFox; [r!f&R
import java.io.*; ia(`3r
|Sm/s;&c6
- AU{Y`j
public class FileAccessI implements Serializable{ U(LLIyZv
ujzfy
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 PQp =bX,
RandomAccessFile oSavedFile; G:3szz
long nPos; p{}4#+-<#H
A$]s{`
Q'qX`K+@`
public FileAccessI() throws IOException lh[?`+A
{ Z #T
this("",0); Y2;2Exp^
} T];dFv-GT
uuxVVgWp{
qXhdU/ =
public FileAccessI(String sName,long nPos) throws IOException \EsT1aT
{ ~>HzAo9e
oSavedFile = new RandomAccessFile(sName,"rw"); UOk\fyD2[
this.nPos = nPos; $ nHD,h
oSavedFile.seek(nPos); .T)wG;+
} TkJ[N4'0
#f<v%
aHVzBcCPh
public synchronized int write(byte[] b,int nStart,int nLen) :.r_4$F:
{ I~:gi@OVV
int n = -1; u88wSe<\X
try{ T@Y, 7ccpd
oSavedFile.write(b,nStart,nLen); yYaoA/0
n = nLen; G[`1Yw$
} o+B)
catch(IOException e) bK.*v4RG
{ WN<g _8QR
e.printStackTrace (); U2l3E*O
} ,uAp;"YJeV
Bp3E)l
n_3R Q6
return n; JXM]tV
} hHGuD2%
DY9]$h*y
IvT><8<G
} t&:L?K)j
[:FiA?O]
a&V;^ /
/* g;v;xlY`N
**SiteInfoBean.java fGO\f;P
*/ ^lAM /
package NetFox; TS#[[^!S
nYFrp)DLK
wD=]U@t`,
public class SiteInfoBean { YZj*F-}
>mai v;
<S041KF.{6
private String sSiteURL; //Site's URL ]"lB!O~
private String sFilePath; //Saved File's Path 7jgj;%
private String sFileName; //Saved File's Name m1U:&{:^
private int nSplitter; //Count of Splited Downloading File T!8^R|!a6
'*`#xNu[
@p L9a1PJv
public SiteInfoBean() >WIc"y.
{//nSplitter的缺省值为5 ~Ix2O
//default value of nSplitter is 5 'gvR?[!t
this("","","",5); X!p`|i
} ocFk#FW
SkE<V0
;Mup@)!j
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -cM1]soT
{ b:D92pH
sSiteURL= sURL; 8.[F3Tk=
sFilePath = sPath; Fq@o_bI
sFileName = sName; &CQO+Yr$l
this.nSplitter = nSpiltter; Y.\x.Hg
$[A\i<#
tqZ+2c<W3
} D]]wJQU2
&cSVOsi
Ic9L@2m
public String getSSiteURL() ,-4NSli
{ kIVQ2hmv
return sSiteURL; H*'1bLzq
} iCE!TmDT
>%k6k1CZ
k~^4
public void setSSiteURL(String value) MQQm3VaKS
{ ]xr0]
sSiteURL = value; W&IG,7tr
} r<ucHRO#
{aUnOyX_
+cfEyiub
public String getSFilePath() eF,F<IJT{
{ MLu!8dgI
return sFilePath; d_,5;M^k
} ];OvV ,*
T&?g)
=~GP;=6
public void setSFilePath(String value) lPZ(c%P
{ n^Ca?|} ,
sFilePath = value; 5 wrRtzf
} x#J9GP.
gSz<K.CT
x9"Cm;H%
public String getSFileName() WVdV:vJ-
{ .|Huzk+
return sFileName; UqOBr2UmG
} ;!MQ@Fi^
mb1mlsE
D%p*G5Bg3
public void setSFileName(String value) C9!t&<\}
{ DB5J3r81
sFileName = value; iT>u&0B-
} USVDDqZ
1f`De`zXzr
v;x0=I&%
public int getNSplitter() m2c'r3UEu
{ @- STo/
return nSplitter; ;=Ma+d#
} C\EIaLN<
>fH0>W+!
Vr1}Zv3K'
public void setNSplitter(int nCount) 6ZqU:^3
{ |9#q7kM
nSplitter = nCount; {A/r)
} EtKq.<SJ
} l88=
2R[v*i^S
a!9'yc
/* b=,BLe\
**Utility.java C/e.BXA
*/ gV2vwe
package NetFox; J~m$7T3Af
IT| h;NUG
g8<ODU0[g
public class Utility { h>/teHy /
?zW'Hi
A2|Bbqd
public Utility() KD kGQh#9
{ V<QpC5
b^/u9
)|~&(+Q?]
} }r:"X<`
|_;kQ(,
//线程睡眠 + [w 0;W_
public static void sleep(int nSecond) e~]P _53
{ I-]G{
try{ p&(0e,`z/
Thread.sleep(nSecond); -9b=-K.y
} 1bFZyD"
catch(Exception e) \p4*Q}t
{ cNWmaCLN$
e.printStackTrace (); h`&TDB2
} Kxsd@^E
} MntmBj-T
SZWNN#w60?
//日志 oGcgd$%ZB
public static void log(String sMsg) _Xf1FzF+a
{ Y&6jFT_
System.err.println(sMsg); 1)X|?ZD]F
} 7{#p'.nc5
$--8%gh dG
q8{Bx03m6
public static void log(int sMsg) imM!Me 0TE
{ Z",0 $Gxu
System.err.println(sMsg); 1=5"j]0hY
} +^AdD8U
} opfnIkCe
/TMVPnvz.
'V&g"Pb
/* ]46h!@~aC
**TestMethod.java v;(cJ,l
*/ V IzIl\<aM
package NetFox; C*YQ{Mz(f
T"g_a|7Tj
+6WjOcu
public class TestMethod { dn h qg3Y
.\b.l@O<Z
b `P6Ox3
public TestMethod() 7!M; ?Y
{ ///xx/weblogic60b2_win.exe ?p{-Yp*h
try{ {]IY;cL
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,$6si
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); z 0?MeH#
SiteFileFetch fileFetch = new SiteFileFetch(bean); [J2evi?
fileFetch.start(); hC$e8t60
} Es[3Ppz
catch(Exception e){e.printStackTrace ();} lMgguu~qg
CEj_{uf|
L'wR$
} =c6d$
^tTM 7
a!o%x
public static void main(String[] args) rCo}^M4Pb
{ b'O/u."O
new TestMethod(); [r2V+b.C
} >l0Qd1
} 8(? &=>@
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