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)); `EVg'?pl
} yM|g|;U
for(int i=0;i<nEndPos.length-1;i++) *|poxT G
{ 2_N/wR#=&
nEndPos = nStartPos[i+1]; HTN$ >QTI
} -p^'XL*Z
nEndPos[nEndPos.length-1] = nFileLength; 4y>(RrVG
} B{99gwMe]
} m0C{SBn-M
~4+8p9f
19&)Yd1
//启动子线程 WP!il(Gr
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; feN!_-
for(int i=0;i<nStartPos.length;i++) Of&"U/^
{ %HVD^. V
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 369Zu4|u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _j>L4bT
nStartPos,nEndPos,i); -U:2H7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]Y=S
fileSplitterFetch.start(); TR?Bvy2s:g
} !^-OfqIHfV
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *F..ZS'$[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 90(UgK&Y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", u`+'lBE,
nEndPos = " + nFileLength); qZP:@r"
// fileSplitterFetch[nPos.length-1].start(); UT~4Cfb
-`g J
wO89&XZ<
//等待子线程结束 ovSH}h!
//int count = 0; ?F25D2[(
//是否结束while循环 G4O3h Y.`
boolean breakWhile = false; &rcdr+'
RB *P0
Z]7tjRvq)
while(!bStop) cXMa\#P
{ +2El
write_nPos(); zNwc((
Utility.sleep(500); t)KPp|&
breakWhile = true; 1S&0
c|+y9(0|y
IE|,~M2
for(int i=0;i<nStartPos.length;i++) >r~|1kQ.
{ ss*5.(y
if(!fileSplitterFetch.bDownOver) i"vDRrDe
{ VYHOk3
breakWhile = false; "7:u0p!
break; ["<5?!bU
} UYH|?Jw!N
} y>4p~
if(breakWhile) R&gWqt/
break; aE}=^%D
80dSQ"y
$f9 ,##/
//count++; O0->sR
//if(count>4) xJ$Rs/9C
// siteStop(); =Z^un&'
} gNG.l
8qn{
87R%ke
System.err.println("文件下载结束！"); w' .'Yu6
} LE<:.?<Z-
catch(Exception e){e.printStackTrace ();} i[mC3ghM6,
} $3lt{ %
9fCiLlI
SlR7h$r'
//获得文件长度 *Rz!i m|
public long getFileSize() d~w}NK[(
{ \dC.%#
int nFileLength = -1; N`J:^,H
try{ :PHUsy
URL url = new URL(siteInfoBean.getSSiteURL()); )Uc$t${en
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8}Fw%;Cb
httpConnection.setRequestProperty("User-Agent","NetFox"); u}Lc|_ea`
tq2-.]Y@U
3| GNi~
int responseCode=httpConnection.getResponseCode(); LZgwIMd
if(responseCode>=400) )e@01l
{ (xI)"{
processErrorCode(responseCode); XYz,NpK
return -2; //-2 represent access is error Y:DNu9
} :!r9 =N9
n$XMsl.>
!l sy&6
String sHeader; $q4XcIX 7
)->-~E}p9
K0d-MC
for(int i=1;;i++) 0IoXDx
{ w`H.ey
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }CB=c]p
//Utility.log(in.readLine()); s!8J.hD'I
sHeader=httpConnection.getHeaderFieldKey(i); F'$9en2I:
if(sHeader!=null) L8,H9T#e
{ -o=P85V
if(sHeader.equals("Content-Length")) r6gt9u:
{ f;@b a[
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); rCnV5Yb0O
break; PCV58n3
} >/*?4
} pq/FLYiv
else 1C5kS[!
break; r| 6S
} ZNL;8sI?>
} f)u*Q!BDD
catch(IOException e){e.printStackTrace ();} {2'74
catch(Exception e){e.printStackTrace ();} }iiG$?|.
7gZVg@
H3UX{|[
Utility.log(nFileLength); eMpEFY
Se;?j-
qH{8n`
return nFileLength; Nj3^"}V
} V1CSXY\2
web8QzLLB
Hb@G*L$
//保存下载信息（文件指针位置） ^J#*n;OQ3A
private void write_nPos() V{AH\IV-
{ <x>k3bD
try{ dEAAm=K,<
output = new DataOutputStream(new FileOutputStream(tmpFile)); +s*l#'Q
output.writeInt(nStartPos.length); OH!$5FEc
for(int i=0;i<nStartPos.length;i++) ]`/R("l[
{ ?-.Ep0/
// output.writeLong(nPos); \/x)BE,
output.writeLong(fileSplitterFetch.nStartPos); o?Tp=Ge
output.writeLong(fileSplitterFetch.nEndPos); _/z)&0DO
} cV=_GE
output.close(); "[".3V
} iEJQ#5))0
catch(IOException e){e.printStackTrace ();} :)+@qxTy
catch(Exception e){e.printStackTrace ();} . ;ea]_Z
} z7.C\l
^b `>/>
G|6|;
//读取保存的下载信息（文件指针位置） W_f"Gk
private void read_nPos() $E9daUt8"J
{ }JpslY*aS
try{ C$..w80/1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +N(YR3
int nCount = input.readInt(); ]\9B?W(#
nStartPos = new long[nCount]; hO<w]jV,
nEndPos = new long[nCount]; (zTI)EV
for(int i=0;i<nStartPos.length;i++) M5ySs\O4
{ < jocfTBk
nStartPos = input.readLong(); FOUs= E[
nEndPos = input.readLong(); T>uWf#&pjs
} Uc4L|:
input.close(); @#ho(_U8
} xO9]yULgu
catch(IOException e){e.printStackTrace ();} Zxxy1Fl#.[
catch(Exception e){e.printStackTrace ();} j@?[vi
} M;TfD
1KIq$lG{ E
v[yTk[zd0
private void processErrorCode(int nErrorCode) <sWcS; x
{ m5;[,He
System.err.println("Error Code : " + nErrorCode); DneSzqO"o
} k4AE`[UE
xV 1Z&l
A7,$y!D
//停止文件下载 RnBmy^l"
public void siteStop() m[Ac'la
{ w KMk|y>
bStop = true; ]{6yS9_tuI
for(int i=0;i<nStartPos.length;i++) -x%`Wv@L
fileSplitterFetch.splitterStop(); DGfQo5#
'hi\98y
Lvj5<4h;
} {LJ6't 8y:
} 'St= izhd
//负责部分文件的抓取 %d#)({N
**FileSplitterFetch.java pA,EUh|H
*/ Z2j*%/
package NetFox; 3;l>x/amk
"%f5ltut3
*=If1qZs
import java.io.*; Q|H cg|
import java.net.*; NUnc"@
|%cO"d^ri
FR6I+@ oX~
public class FileSplitterFetch extends Thread { AW;)_|xM
WKJL< D ]:
%iS]+Sa.K
String sURL; //File URL L(n~@gq
long nStartPos; //File Snippet Start Position =ObtD"
long nEndPos; //File Snippet End Position +e4<z%1
int nThreadID; //Thread's ID _,0!ZP-
boolean bDownOver = false; //Downing is over U+r#YE.
boolean bStop = false; //Stop identical )"Br,uIv:/
FileAccessI fileAccessI = null; //File Access interface IS4K$Ac.
Y6%OV?}v!
H_=[~mJ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException sr@XumT
{ UpseU8Wo
this.sURL = sURL; &trh\\I"
this.nStartPos = nStart; o4'4Hy
this.nEndPos = nEnd; `&[:!U2]F
nThreadID = id; _7"W\gn:9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )hJjVitG
} AbI*/|sY
@%G"i:HZ&
\lIHC{V\
public void run() )bU")
{ +pViHOJu&V
while(nStartPos < nEndPos && !bStop) zp-~'kIJ
{ t}+c/ C%b=
s^R2jueR
!;C(pnE
try{ j?hyN@ns
URL url = new URL(sURL); JU1; /3(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &0Zk3D4
httpConnection.setRequestProperty("User-Agent","NetFox"); U9sub6w6
String sProperty = "bytes="+nStartPos+"-"; @5VZ
httpConnection.setRequestProperty("RANGE",sProperty); =d.W'q|
Utility.log(sProperty); K5rj!*x.o
uN0fWj]
{&qsh9ob
InputStream input = httpConnection.getInputStream(); Dx*oSP.qX
//logResponseHead(httpConnection); ^l9 *h
Awf=yE:
ibUPd."W
byte[] b = new byte[1024]; `|?$; )
int nRead; zR_l^NK
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Jiylrf`o
{ ~6i mkv^ F
nStartPos += fileAccessI.write(b,0,nRead); &-Er n/[
//if(nThreadID == 1) luog_;{h+
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K :ptfD
} F4(U~n<
~M1%,]
c}s3c >`d
Utility.log("Thread " + nThreadID + " is over!"); #N}}8RL
bDownOver = true; t1s@Ub5);I
//nPos = fileAccessI.write (b,0,nRead); {j*+:Gj0V
} T7_rnEOO
catch(Exception e){e.printStackTrace ();} =H?5fT^
} oYx f((x
} 3PeJPw
xl=|]8w
b?L43t,
//打印回应的头信息 $& gidz/w
public void logResponseHead(HttpURLConnection con) w*@Z-'(j
{ S]@iS[|?
for(int i=1;;i++) I@v.Hqg+7
{ <WkLwP3^
String header=con.getHeaderFieldKey(i); ~,1X>N"
if(header!=null) 'Q,<_L"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Q-CVq_\3I
Utility.log(header+" : "+con.getHeaderField(header)); 2mG?ve%m)
else ^E*C~;^S
break; /tP
} FQ^uX]<3j
} `XY[HK
(b!DJ;(O9
{ )K(}~VD
public void splitterStop() vUA`V\
{ xSZw,
bStop = true; W0hLh<Go
} <{j9|mt
> xw+2<
'KG`{K$
} 9a unv
#xB%v
&2^V<(19
/* cFQa~
**FileAccess.java beoMLHp
*//文件访问(定位，写) `dhK$jYD
package NetFox; e{/\znBS%
import java.io.*; L}+!<Ug
S/aPYrk>6
5E8PbV-l
public class FileAccessI implements Serializable{ __[q`
hJ :+*46
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 f5v|}gMAX
RandomAccessFile oSavedFile; !bg3
long nPos; 4g9VE;Gd
ufOaD7
)Ec;krb+
public FileAccessI() throws IOException dewu@
{ b04~z&Xv
this("",0); ~qF9*{~!
} M?o`tWLhF
s zg1.&
MDpXth7
public FileAccessI(String sName,long nPos) throws IOException ) AIZE?oX
{ F=H=[pSe
oSavedFile = new RandomAccessFile(sName,"rw"); $- L)>"
this.nPos = nPos; 1/HZY0em
oSavedFile.seek(nPos); f!yxS?j3
} &wfM:a/c
JkmL'Zk>:
A`KTm(
public synchronized int write(byte[] b,int nStart,int nLen) WJ@,f%=<~
{ +qdK]RR}
int n = -1; uIu0"pv`x
try{ LYKepk
oSavedFile.write(b,nStart,nLen); ~kL":C>2
n = nLen; :;EzvRy
} R[z6 c)
catch(IOException e) ~(c<ioIf
{ A-<qr6q
e.printStackTrace (); sbVeB%k
} D 6(w}W
v1:5r
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return n; CA3.fu3(p
} c{[d@jtO
iL(E`_I<
"371`!%
} -Fb/GZt|
Eb*DP_
Uc&0>_Z
/* 7HzKjR=B
**SiteInfoBean.java 5d)G30
*/ <J- aq;p
package NetFox; #2}S83 k
]fR 3f
TGg*(6'z
public class SiteInfoBean { #xO`k1W.
|(wx6H:
JO _a+Yl
private String sSiteURL; //Site's URL `/"z.~8
private String sFilePath; //Saved File's Path )%Y$FLB
private String sFileName; //Saved File's Name I%%$O'S
private int nSplitter; //Count of Splited Downloading File ?)9 6YX'
M+Dkn3bx
]^s4NXf+
public SiteInfoBean() /({5x[
{//nSplitter的缺省值为5 1[!Idl?m
//default value of nSplitter is 5 \PL92HV
this("","","",5); 1aSuRa
} $BG9<:p
nwz}&nR
eM8u ;i
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :qI myaGQ
{ o'W &gkb9
sSiteURL= sURL; r&^4L
sFilePath = sPath; *@n%K,$v
sFileName = sName; Qg3 -%i/@
this.nSplitter = nSpiltter; xe}"0'g
bvAO(`
J`\%'pEn
} !DLIIKO78
W(EU*~<UC
#U'n=@U@(
public String getSSiteURL() pS51fF9
{ 8^+Qn/b_%
return sSiteURL; 7quhp\
} |rsu+0Mtz
>:8GU f*
9-9`;Z
public void setSSiteURL(String value) eml(F
{ !G,Ru~j5:
sSiteURL = value; o:m:9dn
} 0YW<>Y`6
5'.j+{"
c}$?k@=
public String getSFilePath() ]l`?"X|^
{ Gu9Ap<>!
return sFilePath; Gh|q[s*k
} :QB Wy
H2[S]`?
k'EP->r
public void setSFilePath(String value) L7C!rS
{ 'd'*4 )]k
sFilePath = value; 0t'WM=W<!8
} C {gYrz)
]#KZ W)M
,"5Fw4G6*
public String getSFileName() 2Q0fgH2
{ L:j;;9Sp{
return sFileName; ,accw}G
} J_<ENs-
j8_WEjG
Sycs u_je
public void setSFileName(String value) >ouHR*
{ g;D [XBp
sFileName = value; _/]4:("
} P]bI".A8
u#ag|b/C:
{?$-p%CF`8
public int getNSplitter() 9YwK1[G6/
{ $ nx&(V
return nSplitter; ;n?H/(6X8>
} 2<y!3OeN
L*"Q5NzB]
vdyLwBz:
public void setNSplitter(int nCount) =I-SQI8
{ y_;LTCj?
nSplitter = nCount; c!d>6:\
} I&,gCZ#
} f,wB.MN
"u@)
{=pRU_-^
/* xxpvVb)mF
**Utility.java (&npr96f
*/ :7 Ro9z8
package NetFox; vc0'x4
]>M{Qn*
p(-f$Q(
public class Utility { zUF%`CR
zZ@]Kq;.s
7O84R^!|2
public Utility() Dl_y[9
{ 35|F?Jx.r
//9Ro"
J$JXY@mBSC
} f?}~$agc
B! $a Y
//线程睡眠 +n_`*@SE
public static void sleep(int nSecond) U{6i5;F#H
{ w7GF,a
try{ %%5K%z,R#
Thread.sleep(nSecond); kqxX!
} x=7hOI5u
catch(Exception e) !|}(tqt
{ >T: Yp<
e.printStackTrace (); ZU\TA|
} yyCx;
} i]oSVXx4WC
CvDy;'{y1
//日志 eJD!dGa
public static void log(String sMsg) Q%:#xG5AmE
{ 0kEzi
System.err.println(sMsg); TNs;#Q
} 2@ 4^ 81
B^`'2$3
kH$)0nK
public static void log(int sMsg) $42%H#
{ U6SgV 8
System.err.println(sMsg); Hp`Mp)1s
} 2pa: 3O
} e+J|se4L5
2Hltgt,
[;O 6)W
/* 5@_c<
**TestMethod.java 1~X~"M
*/ F=}-ngx8&
package NetFox; Sg$14B
XHq8p[F
pMJK?- )
public class TestMethod { X[pk9mha
;-Bi~XD
NUB3L
public TestMethod() c o}o$}
{ ///xx/weblogic60b2_win.exe WHh=hts\
try{ t%jB[w&,os
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 'W0?XaEk-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?R2`RvQ
SiteFileFetch fileFetch = new SiteFileFetch(bean); ba_T:;';0
fileFetch.start(); xv! QO
} mRIW9V
catch(Exception e){e.printStackTrace ();} i,G )kt'H
{. r/tV5IH
tmAc=?|Wa
} =1D* JU
/mST<{(_G\
]@@3]
public static void main(String[] args) [&mYW.O<
{ GdN'G
new TestMethod(); B@wQ[
} nU Oy-c
} UH8)r
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