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)); \lQI;b;$
} do.>Y}d
for(int i=0;i<nEndPos.length-1;i++) y7CO%SA
{ \}u/0UF97
nEndPos = nStartPos[i+1]; (Cq 38~mR
} p{W Amly
nEndPos[nEndPos.length-1] = nFileLength; yufw}Lo-
} D|m0Vj b
} qC"`i}7
#I.~+M
}vx,i99W?
//启动子线程 kdlmj[=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fp\mBei
for(int i=0;i<nStartPos.length;i++) P]y{3y:XxM
{ <YEKbnw$o
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O-)[!8r
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =_iYT044p
nStartPos,nEndPos,i); QRKP;aYt
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *{k{
fileSplitterFetch.start(); IDw`k[k
} z"\w9 @W
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &{glwVKV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Qbjm,>H/^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", qLb~^'<iD
nEndPos = " + nFileLength); \b"|p%CL8
// fileSplitterFetch[nPos.length-1].start(); hEZo{0:b"
IAMa
2Q]W
//等待子线程结束 '%ZKvZ-
//int count = 0; _Li.}g@Bd
//是否结束while循环 He4HIZ
boolean breakWhile = false; qzA_ ~=g
$kHXt]fU
+zk5du^gZ
while(!bStop) wme#8/eUk
{ 517wduj
write_nPos(); r#1W$~?>
Utility.sleep(500); ^z{Xd|{"
breakWhile = true; l59 N0G
w6h83m 3
qN' 3{jiPL
for(int i=0;i<nStartPos.length;i++) H Q[
{ <oT1&C{
if(!fileSplitterFetch.bDownOver) v@SHR0
{ .bP8Z=
breakWhile = false; e&:%Rr]x
break; L'`Au/%S}
} p^q/u
} _unoDoB
if(breakWhile) vL[IVBG^
break; R2{]R&wtn0
[_3&
Zos.WS#
//count++; 0QPY+6
//if(count>4) `+vQ5l$;L
// siteStop(); *,:2O&P
} RFFbS{U*
g@s`PBF7`
,YBO}l
System.err.println("文件下载结束！"); ,ZrR*W?iF
} 8EdaqF
catch(Exception e){e.printStackTrace ();} [bX^_ Y
} dyf>T}Iy
FW;}S9u3
-:'%YHxX
//获得文件长度 SB('Nqih
public long getFileSize() 6)ZaK
{ 0F_hXy@K
int nFileLength = -1; sKKc_H3YSH
try{ 3WwCo.q;m
URL url = new URL(siteInfoBean.getSSiteURL()); us1$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c/^:vTF
httpConnection.setRequestProperty("User-Agent","NetFox"); F;_o`h
Qx|HvT2P
g{sp<w0
int responseCode=httpConnection.getResponseCode(); 4Hb"yp$
if(responseCode>=400) cmU0=js.
{ BQ[R)o
processErrorCode(responseCode); T95FoA
return -2; //-2 represent access is error _7';1 D
} !ii(2U
B=^M& {
n{~&^Nby*I
String sHeader; g@M5_I(W
<3N\OV2
eNi#% ?=WB
for(int i=1;;i++) Q<MxbHk9
{ "M2WK6?O5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *\}$,/m['
//Utility.log(in.readLine()); 6|n3Q$p
sHeader=httpConnection.getHeaderFieldKey(i); k'&1,78[l
if(sHeader!=null) mC\<fo-u
{ ?6ssSjR}
if(sHeader.equals("Content-Length")) (6mw@gzr
{ VSCKWYy
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); mAW(j@5sp
break; lf KV%
} _dAn/rj
} L8'4d'N+>
else -6s]7#IC
break; qRcg|']R
} 4Wa$>vz
} l:u1P
catch(IOException e){e.printStackTrace ();} IDqUiN
catch(Exception e){e.printStackTrace ();} vR5X
dQ_'8 )
NM),2%<
Utility.log(nFileLength); .=G3wox3
s[UV(::E
5%V(eR
return nFileLength; qM 1ZCt
} aL;zN%Tw
jpR]V86G
x30|0EHYl[
//保存下载信息（文件指针位置） A0;{$/
private void write_nPos() d!Y%7LmSE@
{ yV L >Ie/
try{ .`J*l=u$
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5\}Y=Pa
output.writeInt(nStartPos.length); l& sEdEA
for(int i=0;i<nStartPos.length;i++) %z[=T@
{ -AVT+RE9z
// output.writeLong(nPos); )>Z@')Uk:
output.writeLong(fileSplitterFetch.nStartPos); OtQ]\:p7
output.writeLong(fileSplitterFetch.nEndPos); l<S3<'&
} $I#~<bW,
output.close(); SJLs3iz_)
} "W4|}plnu
catch(IOException e){e.printStackTrace ();} >,k2|m
catch(Exception e){e.printStackTrace ();} u6Ux nqNc
} 2Q%M2Ua
pBBKfv
'|v<^EH
//读取保存的下载信息（文件指针位置） zT/woiyB`
private void read_nPos() $/JXI?K
{ P@5-3]m=
try{ /RhM6N
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); jY/(kA]}
int nCount = input.readInt(); +:70vZc:V@
nStartPos = new long[nCount]; A>S7Ap4z>
nEndPos = new long[nCount]; 'zMmJl}\vd
for(int i=0;i<nStartPos.length;i++) C9k"QPE
{ \7xc*v [
nStartPos = input.readLong(); yEJ3O^(F
nEndPos = input.readLong(); NL-PQ%lUA
} "la0@/n
input.close(); XknNb{. r
} @{3_7
catch(IOException e){e.printStackTrace ();} GvA4.s,
catch(Exception e){e.printStackTrace ();} +@8, uL
} I3x+pa^]2
HJ"sK5Q
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private void processErrorCode(int nErrorCode) <bhJ>
{ >nK(
System.err.println("Error Code : " + nErrorCode); RASk=B
} TBF{@{.d
,1<6=vL
"OkZ [E)
//停止文件下载 ix?Z:pIS0
public void siteStop() fffWvf
{ 9M|#X1r{%{
bStop = true; o2]Np~`g,
for(int i=0;i<nStartPos.length;i++) 94*MRn1E
fileSplitterFetch.splitterStop(); ) 54cG
69uDc
/Q#eP m
} aGE} EK}
} vt(n: Xk
//负责部分文件的抓取 l#>A.-R*`
**FileSplitterFetch.java Sw[*1C8
*/ +Bt%W%_X
package NetFox; Sv>CVp*
PIQd=%?'
qla=LS\-A+
import java.io.*; `r\/5|M
import java.net.*; [fkt3fS
|-GbHfz
0BjP|API
public class FileSplitterFetch extends Thread { QT1oUP#*
Q4N0j' QA
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String sURL; //File URL 1O)m(0tb[
long nStartPos; //File Snippet Start Position 7(LB}
long nEndPos; //File Snippet End Position OH 88d:
int nThreadID; //Thread's ID y=SpIbn{
boolean bDownOver = false; //Downing is over Y~lOkH[z
boolean bStop = false; //Stop identical UK@hnQU8`
FileAccessI fileAccessI = null; //File Access interface EW]8k@&g
"Nq5FcS9
n4+^f~Y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException />PH{ l
{ 8N#.@\'kz.
this.sURL = sURL; Q5Mn=
this.nStartPos = nStart; Di$++T8"
this.nEndPos = nEnd; [$\VvRu%
nThreadID = id; ._'.F'd
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~"R;p}5"
} [,z>msEB.
l]IQjjJ`
{;JFoe+
public void run() *tDxwD7
{ &&96kg3
while(nStartPos < nEndPos && !bStop) '0qKb*
{ Q b5vyV `
$KGRpI
v?DA>
try{ "(\]-%:7
URL url = new URL(sURL); x.(Sv]+[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /zir$
httpConnection.setRequestProperty("User-Agent","NetFox"); ( M3-S5
String sProperty = "bytes="+nStartPos+"-"; 5* ~EdT
httpConnection.setRequestProperty("RANGE",sProperty); ^7$Q"
Utility.log(sProperty); GN|xd+O_
2>Kn'p
q\fai^_
InputStream input = httpConnection.getInputStream(); P2U[PO
//logResponseHead(httpConnection); ?V)M!
I[LHJ4
TP=#U^g*
byte[] b = new byte[1024]; 5 ^tetDz}
int nRead; H|;BT
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9\6ZdnEKu,
{ ITU6Eq
nStartPos += fileAccessI.write(b,0,nRead); anUH'mcK*
//if(nThreadID == 1) <a D}Ko(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0INlo
} >~G _'~_f
%i.;~>
\e?w8R.6w^
Utility.log("Thread " + nThreadID + " is over!"); G`u";w_
bDownOver = true; $n<X'7@0
//nPos = fileAccessI.write (b,0,nRead); z'Fu} ho
} `ItPTSOi
catch(Exception e){e.printStackTrace ();} }/%^;@q;
} U {sT %G
} =l}XKl->
DDU)G51>d
)TkXdA?.
//打印回应的头信息 82=>I*0Q
public void logResponseHead(HttpURLConnection con) mH4Jl1S&
{ yd`f<Hr<m
for(int i=1;;i++) 'c/Z W
{ {,o =K4CD
String header=con.getHeaderFieldKey(i); QPz3IK%
if(header!=null) t^<ki?*
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Q\Nz^~dQ:Y
Utility.log(header+" : "+con.getHeaderField(header)); >xm:?WR
else Eg]tDPN1
break; #)<WQZ)
} :c&F\Q=
} pQBhheiM
9%bqY9NFd
W}>wRy
public void splitterStop() { Em fw9L
{ 4jz2x #T
bStop = true; X>s'_F?
} ! d" i
:*E#w"$,j
koOp:7r
} kQ $.g<
1}I%yOi)
?\T):o;/
/* ?h|w7/9
**FileAccess.java gn4Sz")
*//文件访问(定位，写) N51RBA
package NetFox; 3*[YM7y
import java.io.*; 7D)i]68E
mMtX:
Zd[6-/-:
public class FileAccessI implements Serializable{ )?,X\/5
Hd0?}w\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 A>Oi9%OY:
RandomAccessFile oSavedFile; N:7;c}~
long nPos; mM;p 7 sJ
B)(ZRH
m<e-XT
public FileAccessI() throws IOException ^-pHhh|g
{ "_36WX
this("",0); Uz; pNWMk
} SXm Hn.?
kX:d?*{KB
ugMfpT)
public FileAccessI(String sName,long nPos) throws IOException G' a{;3
{ tGh!5EZ6`
oSavedFile = new RandomAccessFile(sName,"rw"); HCVMqG!
this.nPos = nPos; BJI"DrF
oSavedFile.seek(nPos); lG!We'?
} `F TA{ba
q.g0Oz@z
aYPD4yX"/
public synchronized int write(byte[] b,int nStart,int nLen) H+2m
{ t"L-9kCM
int n = -1; e8ZMB$byP
try{ J+20]jI
oSavedFile.write(b,nStart,nLen); #[aHKq:?b
n = nLen; I^yInrRh5
} uf&Ke k,
catch(IOException e) K trR+:
{ 0 P-eC|0
e.printStackTrace (); C%\.
} p$OkWSi~
f<aJiVP
^SH8*7l7
return n; Dwp-*QK^G
} O!#bM< *
BD (
@ wJ|vW_.
} j_2yTz"G-
zd+<1R;
| ?])]F
/* CHX- 4-84{
**SiteInfoBean.java 982n G-"
*/ R#i{eE*WF
package NetFox; \z>L,U
,"Nfo`7
('7qJkV
public class SiteInfoBean { 1'>wrGr
b"C1
?#rejA:
private String sSiteURL; //Site's URL mU3 @|a/@0
private String sFilePath; //Saved File's Path XrD@q
private String sFileName; //Saved File's Name AUvUk<a
private int nSplitter; //Count of Splited Downloading File 8@Kvh|
\9GJa"xA`
*D$[@-7
public SiteInfoBean() mUW4d3tE
{//nSplitter的缺省值为5 nd)bRB
//default value of nSplitter is 5 nVVQ^i}`G
this("","","",5); r.T!R6v}
} hs m%o\
C:WXI;*cr
+)eI8o0#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) P,/=c(5\}
{ )FnJLd
sSiteURL= sURL; Y^~Dr|5%
sFilePath = sPath; )k}UjU`!
sFileName = sName; >SR!*3$5
this.nSplitter = nSpiltter; chr^>%Q_
D[ -Gzqh
{x#I&ra
} G uLU7a
`78:TU~5S
L]C|&KP
public String getSSiteURL() |wFfVDp
{ WG0Ne;Ho
return sSiteURL; ev_4!+ko
} /T_@rm
?onTW2cG;
{!`0i
public void setSSiteURL(String value) vdLBf+Zi
{ o2C{V1nB
sSiteURL = value; sAG#M\A6
} )Kw Gb&l&
LyB &u()
AQH\ ;L
public String getSFilePath() 97%S{_2m/
{ L6-zQztn
return sFilePath; ogrh"
} *Fe
E0Y>2HOuL
O*8.kqlgt
public void setSFilePath(String value) `Z3p( G
{ ~T_4M
sFilePath = value; <FfdOK_
} I#m0n%-[
cn~M:LW23
)_\ZUem
public String getSFileName() 6ofi8(n[
{ @FBlF$vG
return sFileName; 0+]ol:i
} K~ 6[zJ4
<lBY
-t:~d:
public void setSFileName(String value) %xq/eC7
{ ;MH<T6b
sFileName = value; 6/Pw'4H9$
} hrRkam!y
+l "z
t69C48}15
public int getNSplitter() G{ 9p.Q
{ ?IWLH-fkP
return nSplitter; xKl!{A9$w
} YF]W<ZpY
k_^|%xJ
7vRFF@eq}
public void setNSplitter(int nCount) t3dvHU&Z:
{ ve [*t`
nSplitter = nCount; GRt1]%l#$
} U;l!.mze
} j~IX
/R2K3E#
EO<{Bj=2
/* NZ}DbA+g;|
**Utility.java =%O@%v
*/ hd@ >p.
package NetFox; ^`96L
8N8N)#A[
n%M-L[n
public class Utility { {Gd<+tQg
_qZ?|;o^
_wC4n }J
public Utility() X~`<ik{q
{ lBbUA)z6
PW[NW-S`c
`H_.<``>
} P2q'P&
\ nIz5J}3
//线程睡眠 LZ97nvK
public static void sleep(int nSecond) km)5?
{ &rcC7v K9
try{ /ynvQ1#uA
Thread.sleep(nSecond); >8pmClVvmR
} "o=*f/M
catch(Exception e) A1mxM5N
{ )@X `B d
e.printStackTrace (); X/5\L.g2
} Z`?Z1SBt
} )N8[@
5iG+O4n%
//日志 Hq[vh7Lux
public static void log(String sMsg) 'g4t !__
{ 1qR[&=/
System.err.println(sMsg); dFu<h
} M:!Twz$
~F</s.
'pJ46"D@m
public static void log(int sMsg) qMk"i@"
{ `qNhB\
System.err.println(sMsg); Ux<2!vh
} tAPr4n!
} (&=<UGY(w
_;;'/rs j
?f\;z<e|
/* DPU%4te
**TestMethod.java i|@lUXBp
*/ +x7b9sHJ
package NetFox; -R~!N#y
`30og]F0YJ
Yt 9{:+[RK
public class TestMethod { @+gr>a1K#
RS$!TTeQ
9^;)~ G
public TestMethod() ^[7ZBmS
{ ///xx/weblogic60b2_win.exe ^x! N]
try{ jkPye{j
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); muAI$IRR
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 'w'PrM,:
SiteFileFetch fileFetch = new SiteFileFetch(bean); AI$r^t1
fileFetch.start(); ]6`]+&
} w3,1ImrXp
catch(Exception e){e.printStackTrace ();} lw.4O^
FD}hw9VyF@
d!V;\w
} [r_YQ*+ej
A]z~Dw3
H%!ED1zpA
public static void main(String[] args) Px!M^ T!Pi
{ D!K){E
new TestMethod(); h)W?8XdM
} Fp)+>oT
} igoXMsifT+
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