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)); K/T4T\
} dZ6\2ok+
for(int i=0;i<nEndPos.length-1;i++) +K2p2Dw(k
{ d2\#Zlu<
nEndPos = nStartPos[i+1]; oGIh:n7 q+
} Nqy)jfyex
nEndPos[nEndPos.length-1] = nFileLength; _;zIH5 H
} Z [[AmxE'l
} T:<mme3v
"UM*(&
YRU1^=v
//启动子线程 %"yy8~|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :t)<$dtf[
for(int i=0;i<nStartPos.length;i++) ]h3{MTr/
{ 3'*}ZDC
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xZ=6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0,{tBo
nStartPos,nEndPos,i); "pA24Ze
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &$H7vdWNy
fileSplitterFetch.start(); RyuI2jEy
} NzBX2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I_.Jo `lK~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); qI=j>x
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", w^EUBRI-
nEndPos = " + nFileLength); ta
// fileSplitterFetch[nPos.length-1].start(); b^s>yN
w *Txc}
[}*xxy
//等待子线程结束 0?80V'
//int count = 0; o],z/MPL
//是否结束while循环 c.?+rcnq
boolean breakWhile = false; |'+ [ '
$ca>bX]
1EmZ/@k/Y
while(!bStop) [TaYNc!\
{ "e;wN3/bF
write_nPos(); ! <O,xI'
Utility.sleep(500); _~}n(?>
breakWhile = true; n/ m7+=]v
7eU|iDYo
^630%YO
for(int i=0;i<nStartPos.length;i++) (?ofL|Cg(
{ e$Npo<u
if(!fileSplitterFetch.bDownOver) >Y)FoHa+/
{ &al\8
breakWhile = false; SbYsa
break; zNh$d;(O$^
} .dw;b~p
} .}*_NU
if(breakWhile) _mG>^QI.
break; 1)N~0)dO
p=jIDM'
$T2n^yz
//count++; `21$e
//if(count>4) <&m `)FJ
// siteStop(); HUWCCVn&
} +cf.In,{
N*{>8iFo4
R64/m9
System.err.println("文件下载结束！"); (i)Ed9~F"
} L=v"5)m2R
catch(Exception e){e.printStackTrace ();} -egu5#d>
} iS#m{1m$$
{0J (=\u
\f-HfYG
//获得文件长度 ] RLEyDB
public long getFileSize() _[p@V_my
{ >sZ207*
int nFileLength = -1; .NX>d@ Kc
try{ 'kE^oX_
URL url = new URL(siteInfoBean.getSSiteURL()); EG oe<.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6i=Nk"d
httpConnection.setRequestProperty("User-Agent","NetFox"); /OsTZ"*.2/
=5D@~?W ZG
Z.{r%W{2
int responseCode=httpConnection.getResponseCode(); ,]cb3nP
if(responseCode>=400) -MTO=#5z
{ r4wnfy
processErrorCode(responseCode); _VFL}<i
return -2; //-2 represent access is error \EC7*a0
} (cpaMn@)g
cuUlr
Q"D%xY
String sHeader; M].D27
>=!$(JgX
bA*T1Db,t>
for(int i=1;;i++) O ]Stf7]%;
{ QVJvuiUh
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); H'2Un(#Al
//Utility.log(in.readLine()); eGW~4zU
sHeader=httpConnection.getHeaderFieldKey(i); n%%u0a%
if(sHeader!=null) 4K<T_B/
{ ?6>rQ6tBv
if(sHeader.equals("Content-Length")) 6JZ$;x{j
{ 6~y7A<[^
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .:?cU#.
break; 6H:'_|G
} 99mo]1_
} 7nOn^f D
else AOVoOd+6
break; A_}%YHb
} 3!<} -sW4
} B_uAa5'
catch(IOException e){e.printStackTrace ();} EC0M0qQ
catch(Exception e){e.printStackTrace ();} u4,b%h.
@"$rR+r'
^{(i;IVG
Utility.log(nFileLength); 5^GFN*poig
!tr /$
.0H!B#9
return nFileLength; /`YbHYNF[
} 8C4=f
69tT'U3vb$
7J$5dFV2
//保存下载信息（文件指针位置） wG2-,\:
private void write_nPos() 0Q= o"@
{ GK.U_`4?
try{ QnPgp(d<
output = new DataOutputStream(new FileOutputStream(tmpFile)); MI<XLn!*
output.writeInt(nStartPos.length); z6 A`/ jF}
for(int i=0;i<nStartPos.length;i++) B$kp\yL
{ f8X/kz
// output.writeLong(nPos); ~hxo_&
output.writeLong(fileSplitterFetch.nStartPos); WKB@9Vfju
output.writeLong(fileSplitterFetch.nEndPos); /naGn@m5u
} 7IV:X _y
output.close(); y9'F D5\s
} kn1+lF@
catch(IOException e){e.printStackTrace ();} /qalj\ud
catch(Exception e){e.printStackTrace ();} nM,5KHU4a
} [AHZOA
i<%
I-`qo7dQ_S
//读取保存的下载信息（文件指针位置） W=)wiRQm
private void read_nPos() eODprFkt}
{ ^68BxYUoD\
try{ c?1:='MC
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); xw%'R-
int nCount = input.readInt(); 3ZKaqwK
nStartPos = new long[nCount]; 9X2lH~C
nEndPos = new long[nCount]; `'^&* 7,
for(int i=0;i<nStartPos.length;i++) /|. |y S9
{ _Mis-K:]{?
nStartPos = input.readLong(); WP-'gC6K=
nEndPos = input.readLong(); Fo1|O&>
} !agtgS$qII
input.close(); /\B[lRn
} Q, !b
catch(IOException e){e.printStackTrace ();} >5|;8v-r
catch(Exception e){e.printStackTrace ();} x# &ZGFr~
} d{LQr}_o$$
rH<iUiA?O
$CYB&|d
private void processErrorCode(int nErrorCode) .$,.w__m~
{ m#oZu {
System.err.println("Error Code : " + nErrorCode); VN1a\
} }M I9?\"q
cLD-,v;c
i%R2#F7I
//停止文件下载 43?J~}<Vs
public void siteStop() +J~q:b.
{ XS'0fq a
bStop = true; 8/|~E
for(int i=0;i<nStartPos.length;i++) oQvG3(.
fileSplitterFetch.splitterStop(); xedbr
sN `NZyG
bof{R{3q
} cP~?Iz8nD
} s: .5S
//负责部分文件的抓取 1K;i/
**FileSplitterFetch.java zFtwAa=r
*/ X[cSmkp7
package NetFox; ^5l4D3@E
CbA2?(1o1
V %cU@
import java.io.*; ]v^;]0vcr
import java.net.*; 9N[vNg<n
*<**rY*
Z`l97$\
public class FileSplitterFetch extends Thread { EPz$`#Sh"
-pRyN]YD
X%1fMC
String sURL; //File URL 8'2lc
long nStartPos; //File Snippet Start Position PG1#Z?_
long nEndPos; //File Snippet End Position s)e; c<(/
int nThreadID; //Thread's ID k_=~ObA$g
boolean bDownOver = false; //Downing is over BlVk?n
boolean bStop = false; //Stop identical ?6bk&"T?
FileAccessI fileAccessI = null; //File Access interface 4^KoHeM6
rX%qWhiEJ
j;O{Hvvz
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ='7n
{ USnKj_e
this.sURL = sURL; "$Wi SR
this.nStartPos = nStart; <9S?wju4W'
this.nEndPos = nEnd; KJwkkCE/=
nThreadID = id; ]xhmM1$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2wWL]`(E
} NAj1ORy4pX
s68EzFS
*6)u5
public void run() %^l77:O
{ m4@y58n=
while(nStartPos < nEndPos && !bStop) V;Zp3Qo!
{ fNi&1J-/
u_o>v{&i
6NCa=9
try{ \kiCczW_
URL url = new URL(sURL); -o+_PL $\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fuQ|[tpvQG
httpConnection.setRequestProperty("User-Agent","NetFox"); eo4<RDe<
String sProperty = "bytes="+nStartPos+"-"; gev7eGH<
httpConnection.setRequestProperty("RANGE",sProperty); yT42u|xZA
Utility.log(sProperty); j~G^J
vO1P%)
E5lC'@Dcz
InputStream input = httpConnection.getInputStream(); $a6&OH/
//logResponseHead(httpConnection); vpY|S2w)Bp
\<VwGbzFi
XbJ=lH
byte[] b = new byte[1024]; RGGP6SDc
int nRead; &50Kn[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #ZIV>(Q\H
{ N1Y*IkW"
nStartPos += fileAccessI.write(b,0,nRead); VwoCRq*
//if(nThreadID == 1) kNW&rg
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t%Z_*mIfmE
} ??rx\*,C</
$&m^WrZaY
nm*!#hx
Utility.log("Thread " + nThreadID + " is over!"); $7aRf'
bDownOver = true; ^sq3@*hCw
//nPos = fileAccessI.write (b,0,nRead); Kg>+5~+E?q
} L_jwM^8
catch(Exception e){e.printStackTrace ();} _Bh-*l?K>
} k6~k
} :&`Yz
c3|;'s
yov:JnWo
//打印回应的头信息 [^W4%S
public void logResponseHead(HttpURLConnection con) J1"u,HF*(
{ cW),Y|8
for(int i=1;;i++) !+IxPn
{ U<eVLfSij
String header=con.getHeaderFieldKey(i); Y[;Pl$
if(header!=null) +I2P{7
//responseHeaders.put(header,httpConnection.getHeaderField(header)); pM\)f
Utility.log(header+" : "+con.getHeaderField(header)); B4&@PX"'>,
else r{kV*^\E
break; tqrvcnQr^
} 5SX0g(C
} ,u(g#T
N7Z&_$Bx
[*?P2.bf
public void splitterStop() #l-,2C~
{ ']f]:X;6w
bStop = true; P]+^^U
} Tp<=dH%$%"
]k{cPK
ZzI^*Nyg
} M!=v"C#
<HG~#oBRq
Bw"L!sZ
/* !cnH|ePbI
**FileAccess.java f9JD_hhP'
*//文件访问(定位，写) s.KJYP
package NetFox; ]&VD$Z984r
import java.io.*; U%_a@&<
I~"-
Yq/|zTe{
public class FileAccessI implements Serializable{ QE!cf@~n"
|82V`CV
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >Q+a'bd w
RandomAccessFile oSavedFile; ,D3q8?j
long nPos; "S[VtuxPCU
d[rxmEXht
lyZof_/*
public FileAccessI() throws IOException g@nk0lQewj
{ + 7E6U*
this("",0); /D8cJgH-
} jzEimKDE's
<g,k[
O(/K@e
public FileAccessI(String sName,long nPos) throws IOException 1WcT>_$
{ J~<:yBup}
oSavedFile = new RandomAccessFile(sName,"rw"); 4pq>R
this.nPos = nPos; vD1jxk'fd
oSavedFile.seek(nPos); BD=;4SLT
} )R,*
%<DRrKt
Z#>k:v
public synchronized int write(byte[] b,int nStart,int nLen) AGCqJ8`|T
{ RPaB4>
int n = -1; m^T$H_*;
try{ 6Om-[^
oSavedFile.write(b,nStart,nLen); Ko''G5+
n = nLen; ~v,LFIT
} )OH!<jW
catch(IOException e) i>,5b1x~
{ RLulz|jC
e.printStackTrace (); A1%V<im@Z
} kf-ZE$S4
N4fuV?E`
ENJ]
return n; giaO7Qh~
} HE+VanY![
f#JLE+0Y
LUo3y'
} _vU,avw
oi"Bf7{
z0g]nYN%
/* c q3CN@
**SiteInfoBean.java (eO0Ic[c
*/ 4G_dnf_
package NetFox; 92 Pp.Rh
"5dh]-m n
%iD>^Dp
public class SiteInfoBean { *A,=Y/
R"O9~s6N
1P2%n[y
private String sSiteURL; //Site's URL Q `E{Oo,
private String sFilePath; //Saved File's Path %Si3t2W/
private String sFileName; //Saved File's Name zG& N5t96X
private int nSplitter; //Count of Splited Downloading File KM0#M'dXy
HNU[W8mg8
c}v:X Slh7
public SiteInfoBean() S8"X7\d{
{//nSplitter的缺省值为5 b55|JWfC`
//default value of nSplitter is 5 Nob(bD5SpE
this("","","",5); w0*6GCP
} 8 (.<
#C>pA<YJzK
1uXtBk6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) TF=S \ Q
{ 2N)Ywqvj
sSiteURL= sURL; S$JM01
sFilePath = sPath; sL&u%7>Re
sFileName = sName; ;xth#j
this.nSplitter = nSpiltter; 5YC(gv3/
$yCj80m\
'{:(4>&
} `/+7@~[RU
j*xens$)
`fc*/D
public String getSSiteURL() &Puu Xz<
{ fG,qax`:c
return sSiteURL; Vs07d,@w>
} PCaa_ 2
Y =`3L
Z6h.gaQ7 H
public void setSSiteURL(String value) ~}ewna/2
{ DMs|Q$XB
sSiteURL = value; bQ .y,+
} 2_F`ILCML
,cC4d`
F=P|vYL&&
public String getSFilePath() OH)SdSBz
{ *"e[au^8*b
return sFilePath; UNY>Q7
} mLq?-&F
(1jkZ^7
O^:Pr8|{J
public void setSFilePath(String value) >T!n* -Zn
{ -OkKLub
sFilePath = value; s}?98?tYB
} 7Q[P
Kw?,A
W%h<@@c4,
public String getSFileName() E-"Jgq\aC
{ MESQAsx%
return sFileName; }W|CIgF*
} gJF;yW4
1m![;Pg3
'GW@P
public void setSFileName(String value) #x%O0
{ {UPIdQ'g
sFileName = value; HQUL?URt
} 41C=O@9m
KR522YW
uNRGbDMA=
public int getNSplitter() 3(PU=
{ qmL!"ZRLF
return nSplitter; "?S#vUS+ 2
} b?y1cxTT
c|O5Vp}
3}T&|@*
public void setNSplitter(int nCount) K1+,y1c
{ m=}kGzIY4
nSplitter = nCount; @wa/p`gj5w
} km|~DkJ\a`
} NKI&n]EO
c2F`S1Nu<
P)}:lTe
/* UHCx}LGe
**Utility.java gXfAz,
*/ `o*eLLk
package NetFox; ]kKsGch
1zp,Suv
}h]:I'R!
public class Utility { 68_UQ.
)0'O!O
{9=U6m^R2
public Utility() Tw`l4S&
{ Hv IN'
p,1RRbyc
je{5iIr3/
} #pVk%5N
|6;.C1\,
//线程睡眠 |mM7P^I
public static void sleep(int nSecond) h\ybh
{ Y}WO`+Vf5
try{ Lh,<q >t
Thread.sleep(nSecond); Jq; }q63:
} /y-P)3_
catch(Exception e) HL!-4kN <$
{ x)GoxH~#
e.printStackTrace (); #IXQ;2%E
} \Lc]6?,R
} HmiwpI
:c.i Z
//日志 k&?QeXW
public static void log(String sMsg) yT,UM^'
{ +,KuYa{lu
System.err.println(sMsg); +X- k)9
} ![V<vIy
+0a',`yc
p1D-Q7F
public static void log(int sMsg) Ri3m438
{ Z?@07Y[|K
System.err.println(sMsg); Q^F-8
} ilHj%h*z
} !#?tA/t@
< xV!vN
tN0>5'/
/* G.N3R
**TestMethod.java ~KNxAxyVi
*/ 3&zmy'b*:
package NetFox; f2Slsl;
C[Fh^
ew0 )
public class TestMethod { U?rfE(!
2Hd6
iN)@Cu7
public TestMethod() Gmc"3L
{ ///xx/weblogic60b2_win.exe yZ P+
try{ F 4hEfO3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); tJn2:}-s
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +u Lu.-N
SiteFileFetch fileFetch = new SiteFileFetch(bean); #z~oc^J^T
fileFetch.start(); z/TZOFaM
} M6I1`Lpf
catch(Exception e){e.printStackTrace ();} ae<KUThm.
&0lNj@/
uI%[1`2N-
} C/w;g3
~Ch`A@=5
JxWHrsh[
public static void main(String[] args) ML]?`qv '
{ [_~U<
new TestMethod(); DUtpd|
} 5N6%N1
} `BvcIn4do
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