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)); :7N3N
} + bhym+
for(int i=0;i<nEndPos.length-1;i++) ewsKH\#
{ ]LPQYL
nEndPos = nStartPos[i+1]; cFd >oDS
} i=FQGWAUu
nEndPos[nEndPos.length-1] = nFileLength; `ejUs]SR
} v`q\6i[-
} XkKC!
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wt}9B[
//启动子线程 o6kNx>tc)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; u<ySd?
for(int i=0;i<nStartPos.length;i++) eHg3}b2r
{ "](6lB1Oe
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7XrfuG*L$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), cvsz%:Vs
nStartPos,nEndPos,i); z+2V4s=
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wgeNs9L
fileSplitterFetch.start(); pj|pcv^
} Q'B6^%:<~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?@6b>='!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); q(^Q3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]Z<_ "F
nEndPos = " + nFileLength); c/W=$3
// fileSplitterFetch[nPos.length-1].start(); f5RE9%.#~
u?+bW-D'd
Wa/g`}
//等待子线程结束 3M*Bwt;F_
//int count = 0; }w-wSkl1
//是否结束while循环 G1T^a>tj4
boolean breakWhile = false; Q'apG)0I
!v#xb3"/
fg%&N2/(.B
while(!bStop) _,h@:Xij
{ =(AtfW^H
write_nPos(); n_K~vD
Utility.sleep(500); V)o,1
breakWhile = true; \J^
0CvsvUN@
-l+P8:fL~
for(int i=0;i<nStartPos.length;i++) v"u^M-_
{ ][PzgzG
if(!fileSplitterFetch.bDownOver) ~o3Hdd_#}N
{ C}g9'jY
breakWhile = false; XdgUqQb}
break; Zwt;d5U
} D6D1S/:ij'
} Z~G my7h(
if(breakWhile) PnT)LqEF
break; &FdWFt=X
$*[{J+t_
dBCbL.!
//count++; |BMV.Zi
//if(count>4) Rxpn~QQ
// siteStop(); K2_Qu't0$
} mumXUX
]pA(K?Lbg
: DG)g3#
System.err.println("文件下载结束！"); *2"6fX[
} >/f_F6ay#
catch(Exception e){e.printStackTrace ();} tEd.'D8 s
} qgt[~i*
#eP LOR&q
Ha>*?`?yI
//获得文件长度 s,VXc/
public long getFileSize() Eq%@"-mo
{ 0:Xxl76v4
int nFileLength = -1; zkM"cb13q/
try{ iItcN;;7
URL url = new URL(siteInfoBean.getSSiteURL()); >>dm}X
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KP;(Q+qTx
httpConnection.setRequestProperty("User-Agent","NetFox"); pC,o2~%{
+H/jK@
YEu1#N
int responseCode=httpConnection.getResponseCode(); 2Tav;LKX
if(responseCode>=400) %3;Fgky
{ <hnCUg1
processErrorCode(responseCode); Ko>&)%))$X
return -2; //-2 represent access is error oj,lz?
} '&O/g<Z}q
dGfVZDsr]
tL SN`6[:
String sHeader; xZ5M/YSyG
A?Qa 4i
3q[WHwmm
for(int i=1;;i++) W|k0R4K]]
{ ~%u|[$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $S*4r&8ZD
//Utility.log(in.readLine()); Z!xVgM{
sHeader=httpConnection.getHeaderFieldKey(i); |xr%6 [Ff
if(sHeader!=null) $$Vt7"F
{ _;A $C(
if(sHeader.equals("Content-Length")) 57{oh")
{ W_O)~u8
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); C8N{l:1f]
break; ~\nBjM2
} inPJ2uBD\^
} `7aDEzmJ
else jg 2qGC
break; E{xVc;t
} p_*M:P1Ma4
} a>4uiFiv
catch(IOException e){e.printStackTrace ();} ?i\B^uB
catch(Exception e){e.printStackTrace ();} BIaDY<j90
WzW-pV]
wCs3:@UH
Utility.log(nFileLength); C`rLj5E%
z9 u$~
:Br5a34q
return nFileLength; ;P&y,:<m:
} 1 "TVRb
7x]4`#u
31^cz*V
//保存下载信息（文件指针位置） wyx(FinIH
private void write_nPos() T&Xl'=/
{ >>l`,+y
try{ uD_v!
output = new DataOutputStream(new FileOutputStream(tmpFile)); X#xFFDzN
output.writeInt(nStartPos.length); %sh>;^58P
for(int i=0;i<nStartPos.length;i++) &MmU
{ Hi!Jj
// output.writeLong(nPos); Mj>}zbpk/
output.writeLong(fileSplitterFetch.nStartPos); &ej8mq"\
output.writeLong(fileSplitterFetch.nEndPos); S&O3HC
} p]D]: Z}P
output.close(); Op.8a`XLt&
} S-+"@>{HJ
catch(IOException e){e.printStackTrace ();} s6*ilq1
catch(Exception e){e.printStackTrace ();} .%EL\2
} Rx07trfN
kEeo5XN
e;bYaM4UX
//读取保存的下载信息（文件指针位置） Mpue
private void read_nPos() Mvj;ic6iK
{ H?1xjY9sl
try{ <mA'X V,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *F^wtH`
int nCount = input.readInt(); 9L0GLmLk1u
nStartPos = new long[nCount]; 72W,FU~OD
nEndPos = new long[nCount]; I7+9~5p
for(int i=0;i<nStartPos.length;i++) ~8 H_u
{ +1JH
nStartPos = input.readLong(); p1pQU={<
nEndPos = input.readLong(); u*S=[dq
} qIUfPA=/_
input.close(); %A1@&xrbl
} R;whW:Tx
catch(IOException e){e.printStackTrace ();} gieN9S
catch(Exception e){e.printStackTrace ();} Z0!5d<
} L(S'6z~_9
z2gk[zY&
Zv]x'3J#Y
private void processErrorCode(int nErrorCode) d9*hBm
{ <`X"}I3ba
System.err.println("Error Code : " + nErrorCode); $yDWu"R8
} vgt]:$
GY3Wj
;rI@*An
//停止文件下载 '#NcZy
public void siteStop() [97:4.
{ XLk<*0tp
bStop = true; 2I3h MD0
for(int i=0;i<nStartPos.length;i++) \?>Hu v
fileSplitterFetch.splitterStop(); c@[:V
CQ7{1,?2
G2 ]H6G$M
} !J1rRPV
} e:E0"<
//负责部分文件的抓取 {_N,=DQ!
**FileSplitterFetch.java |@?%Ct
*/ _$NIp `d
package NetFox; q>f<u&
(z7vl~D
rt3qdk5U
import java.io.*; pA.J@,>`}
import java.net.*; >4Y3]6N0.F
rD?L
2n><RZ/9
public class FileSplitterFetch extends Thread { =@Dwlze
I4;A8I
*D4hq=
String sURL; //File URL V6$xcAE"</
long nStartPos; //File Snippet Start Position 0`.^MC?
long nEndPos; //File Snippet End Position ^m#-9-`
int nThreadID; //Thread's ID R_]{2~J+
boolean bDownOver = false; //Downing is over iUMY!eqp
boolean bStop = false; //Stop identical K/m3
FileAccessI fileAccessI = null; //File Access interface VUTacA Y>L
?7:KphFX)
hc (e$##
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0.$hn
{ Rtb :nJ8
this.sURL = sURL; v}@xlB=
this.nStartPos = nStart; M7f;Pa
this.nEndPos = nEnd; #ywk|k5z]
nThreadID = id; M)*\a/6?{
fileAccessI = new FileAccessI(sName,nStartPos);//定位 W)'*m-I
} MUOa@O,
bQe^Px5 !.
4p;aS$Q
public void run() 4v p
{ kP#e((f,
while(nStartPos < nEndPos && !bStop) A,su;Qh
{ i'd2[A.7I
,h|qi[7
f~E*Zz`;
try{ Vc^HVyAx@n
URL url = new URL(sURL); _0+0#! J!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jR=s#Xz
httpConnection.setRequestProperty("User-Agent","NetFox"); >56>*BHD
String sProperty = "bytes="+nStartPos+"-"; x@mL $
httpConnection.setRequestProperty("RANGE",sProperty); f)]%.>
Utility.log(sProperty); AV 8n(
"G>3QL+O|
NmK8<9`u
InputStream input = httpConnection.getInputStream(); wB'zuPAK6
//logResponseHead(httpConnection); 6nhMP$h
U$oduY#
\ w3]5gJZ
byte[] b = new byte[1024]; %B.D^]S1:
int nRead; C]^H&
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 80A.<=(=.
{ [dtbkQt,c
nStartPos += fileAccessI.write(b,0,nRead); =to=8H-
//if(nThreadID == 1) !=;XBd-
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); aA7=q=
} W\1i,ew>
f%5zBYCgC
XC{eX&,2x
Utility.log("Thread " + nThreadID + " is over!"); \~P=U;l=pO
bDownOver = true; (}.@b|s
//nPos = fileAccessI.write (b,0,nRead); Y*_)h\f
} <2C7<7{7
catch(Exception e){e.printStackTrace ();} A!1;}x
} rt JtK6t
} H>r!i4l
3_JCU05H}
CctJFcEZ
//打印回应的头信息 >-&R47G
public void logResponseHead(HttpURLConnection con) E.1J2Ne
{ MX@IHc
for(int i=1;;i++) >#ZUfm{k$
{ ^ 9!!;)
String header=con.getHeaderFieldKey(i); ;lYHQQd!,
if(header!=null) P`r55@af4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); d[rv1s>i
Utility.log(header+" : "+con.getHeaderField(header)); &.TTJsKG h
else U%0Ty|$Y
break; gGfoO[B
} 8Sz})UZ
} Spt?>sm
Y8flrM2CwG
J>d.dq>r
public void splitterStop() O-)-YVU
{ " RxP^l
bStop = true; 0!v->Dk
} 1;<R#>&,*
x@8a''
#^+DL]*l
} "RIZV
fNGZo
HR}bbsqxVf
/* pW4 cX
**FileAccess.java YBh'EL}P
*//文件访问(定位，写) r'gOVi4t1*
package NetFox; {v3P9s(
import java.io.*; yDNOtC|
HSq}7S&U
r(gXoq_w
public class FileAccessI implements Serializable{ !?Wp+e6
I%urz!CNE*
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 U*.0XNKp{
RandomAccessFile oSavedFile; }-~l!
long nPos; J90v!p-
YJ$1N!rG
m,fAeln
public FileAccessI() throws IOException a&vY!vx3
{ 4tY ss
this("",0); W`^@)|9^)
} E!S 78z:
nS>8bub30
[$[:"N_
public FileAccessI(String sName,long nPos) throws IOException *hcYGLx r
{ cu+FM
oSavedFile = new RandomAccessFile(sName,"rw"); [z7bixN
this.nPos = nPos; J4Dry<
oSavedFile.seek(nPos); Mw9 \EhA
} V')0 Mr
$ImrOf^qt
Y`?-VaY
public synchronized int write(byte[] b,int nStart,int nLen) Agrk|wPK
{ \6\<~UX^
int n = -1; qP<Lr)nUH
try{ Yw0[[N<SW
oSavedFile.write(b,nStart,nLen); 4*$G & TX
n = nLen; e1P"[|9>R
} 7g3>jh
catch(IOException e) ;J7F J3n
{ o=`C<}
e.printStackTrace (); jlxpt)0i
} 2#k5+?-c61
.9.2Be
y|wc,n%L>
return n; ?,/U^rf^4
} NIw\}[-Z0E
5xL~`-IA&v
0Lb4'25.
} Jec'`,Y
K#.
zP<pEI
/* <I;2{*QI2
**SiteInfoBean.java ZRYEqSm
*/ n'emNRa
package NetFox; 0V?F'<qy
8g7<KKw
-44&#l^}_u
public class SiteInfoBean { j)q\9#sI/(
&4_qF^9J
i&n'N8D@
private String sSiteURL; //Site's URL /t(C>$ }p
private String sFilePath; //Saved File's Path cv`~y'?D
private String sFileName; //Saved File's Name c%qv9
private int nSplitter; //Count of Splited Downloading File C`q@X(_
?Q&yEGm(
_Zr.ba
public SiteInfoBean() b".L_Ma1*
{//nSplitter的缺省值为5 [<KM?\"1<
//default value of nSplitter is 5 8,uB8C9
this("","","",5); TjG4`:*y#m
} nl9P, d
,UuH}E
&ot/nQQ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) t]e;;q=L.
{ N\bocMc,X
sSiteURL= sURL; h\'n**f_x
sFilePath = sPath; %'T #pz
sFileName = sName; =)7s$ p
this.nSplitter = nSpiltter; LcE+GC
."Y e\>k
bwl|0"f+`
} gmm.{%1_I;
vI@%Fg+D
wiBVuj#
public String getSSiteURL() Ot`VR&}
{ 7sXxq4
return sSiteURL; > %KuNy{
} +}a ]GTBgA
h5K$mA5
CoA6
public void setSSiteURL(String value) 8}(]]ayl
{ oqeSG.1
sSiteURL = value; }C|dyyr
} )Dz+X9;g+
'{B!6|"X
~^cMys |'
public String getSFilePath() x]33LQ1]
{ Cn[0(s6
return sFilePath; 7>~5jYP
} of@#:Qs
c}0@2Vf
,f&5pw =
public void setSFilePath(String value) [2Ud]l:6E
{ ;{[.Zu
sFilePath = value; y.Z?LCd<
} } GiHjzsR
gatB QwJb9
cA:*V|YV`
public String getSFileName() mbueP.q[?
{ >&U,co$>
return sFileName; ',S'.U
} JGQjw(Xs
R`~z0d.
fX|Y;S-@+
public void setSFileName(String value) ]i)j3WDz]
{ j.@\3'
sFileName = value; $O5UyKI
} STaA]i}P
eD#hpl
'Un" rts
public int getNSplitter() )[|3ZP`
{ IOV(seEY
return nSplitter; ]S5JUAGkE*
} y?q*WUh
$81*^
)d>!"JB-
public void setNSplitter(int nCount) }_68j8`
{ ~Onoe $A[<
nSplitter = nCount; z'EajBB\f
} v@d
} :EA\)@^$R
TG5XSy
'uxX5k/D@t
/* s]JF0584
**Utility.java _> *jH'
*/ yYH0v7vx+
package NetFox; |x-S&-
Mwr"~?\\
.uk>QMs1
public class Utility { yT,.z 0
ok4@N @
1{r)L{]
public Utility() }7.PH'.8
{ ;y2/-tL?
d:U9pC$
[`):s= FC
} #gcF"L||
=Yt R`
//线程睡眠 #*(td<Cp
public static void sleep(int nSecond) L~NbdaO
{ =Fr(9(
try{ i|m3mcI%2
Thread.sleep(nSecond); 6Avw-}.7>
} E!P yL>){
catch(Exception e) y7i*s^ys{
{ K]9"_UnN
e.printStackTrace (); k4[|'Dk?
} d$Pab*
} 2FW\O0U
oczN5YSt
//日志 `6xkf&Kt
public static void log(String sMsg) lh;:M-b9
{ >M/V oV
System.err.println(sMsg); ZXuv CI
} %GS(:]{n
#: [<iSk
Ch3jxgQY
public static void log(int sMsg) Ub* wuI
{ uPl\I6k
System.err.println(sMsg); `p;I}
} 9Q+'n$s0^
} la+[bm<v
SrK)t.oK
8{X"h#
/* 3^6 d]f
**TestMethod.java ikSt"}/hd
*/ -xA2pYz"
package NetFox; T]=r Co
+lMX{es\O
Y1J=3Y
public class TestMethod { A"rfZ`
LpqO{#ZG
ftF@Wq1f
public TestMethod() / :n#`o=;
{ ///xx/weblogic60b2_win.exe F 70R1OYU
try{ fV'ZsJ N
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Gvr@|{k
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \hEN4V[
SiteFileFetch fileFetch = new SiteFileFetch(bean); o_^?n[4
fileFetch.start(); K%RxwM
} #a8B/-
catch(Exception e){e.printStackTrace ();} VN\W]jT
(j3xAA
d5gR"ja
} -3=#u_
?qWfup\S
@6]sNm
public static void main(String[] args) xM&Wgei]10
{ 8Hn|cf0
new TestMethod(); #kaY0M
} @dPTk"P
} y3o25}"
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