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)); 6OB3%R'p
} h\2iArw8
for(int i=0;i<nEndPos.length-1;i++) F'-XAI <3
{ kA> e*6
nEndPos = nStartPos[i+1]; lD{*Z spz
} f40OVT@g
nEndPos[nEndPos.length-1] = nFileLength; 9o4h~Imu
} 1xr2x;
} (I#mo2
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G)q;)n;*=
//启动子线程 ia (&$a8X
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :cf#Tpq"
for(int i=0;i<nStartPos.length;i++) r@}8TE*|P
{ FU(2,Vl
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Bg] %
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Ylyk/
nStartPos,nEndPos,i); gZiwXb
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0cDP:EzR;
fileSplitterFetch.start(); RL)~J4Y
} 8rjD1<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /=T:W*C
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7xFZJ#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", lwz\"8
nEndPos = " + nFileLength); 7%W1M@
// fileSplitterFetch[nPos.length-1].start(); ;!C_}P
a`[9<AM1#
{5fL!`6w
//等待子线程结束 O~v~s 'c&
//int count = 0; ^^lx Ot
//是否结束while循环 :[CEHRc7x
boolean breakWhile = false; mlPvF%Ba
` Z/ MQ
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while(!bStop) 'tDUPm38
{ >_\[C?8
write_nPos(); `H 'wz7
Utility.sleep(500); ^KnK \
breakWhile = true; &po!X )
EqGpo_
~ivOSr7s}
for(int i=0;i<nStartPos.length;i++) gX7R-&[UD
{ IT)3Et@Y
if(!fileSplitterFetch.bDownOver) C#4_`4{
{ >q0%yh-
breakWhile = false; c%bzrYQvA;
break; !{{gL=_@
} i"=lxqWeaV
} dWY{x47
if(breakWhile) m@u%3*:
break; yn"4qC#Z
tj*/%G{Y
O;5lF
//count++; ?;H}5>^8P
//if(count>4) }'faf{W
// siteStop(); Yg,;l-1
} ,<'>jaC
74a@/'WbE
oam;hmw
System.err.println("文件下载结束！"); ky-nP8L}
} 9e c},~(
catch(Exception e){e.printStackTrace ();} J3(E{w8Q
} 4 R(m$!E!
0\vG <
QxN1N^a0
//获得文件长度 qE|syA9
public long getFileSize() &r~s3S{pQ
{ QQ_7Q^
int nFileLength = -1; H9PnJr8 \
try{ 1q@R04i
URL url = new URL(siteInfoBean.getSSiteURL()); X:I2wJDs\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jr_z ?
httpConnection.setRequestProperty("User-Agent","NetFox"); f0j]!g
<hj2'dU
GmaNi
int responseCode=httpConnection.getResponseCode(); lGBg8/[
if(responseCode>=400) Lr5{c5M
{ <,rOsE6
processErrorCode(responseCode); O`@- b#
return -2; //-2 represent access is error ggiy{CdR
} oP9 y@U
lSW'qgh
IM7<z,*oF
String sHeader; h6OQeZ.
]@ke_' "
wpN3-D
for(int i=1;;i++) fISK3t/=C
{ vV*J;%MO
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); HZZZ [km
//Utility.log(in.readLine()); \/?J)k3H.
sHeader=httpConnection.getHeaderFieldKey(i); =4co$oD}
if(sHeader!=null) l_yF;5|?z
{ ;>f\fhi'
if(sHeader.equals("Content-Length")) 3l45(%g+
{ >*VvV/UU
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]wdE :k,D
break; y`j=(|DV
} (tOhuSW
} G_J}^B*?%v
else \~z$'3H`
break; LiV&47e*>
} jx}'M$TA
} ~59lkr8
catch(IOException e){e.printStackTrace ();} ooUVVp
catch(Exception e){e.printStackTrace ();} -{ 1P`&G
<Q/)SN6_E
GCq4{_B\Q
Utility.log(nFileLength); *d;TpwUI
vdAd@Z~\
-l57!s~V
return nFileLength; pCrm `hy(
} lFnYQab
lTP#6zqfv
Xd5s8C/}
//保存下载信息（文件指针位置） o2U5irU
private void write_nPos() t@9-LYbL
{ V){Io_"
try{ r6'dEa
output = new DataOutputStream(new FileOutputStream(tmpFile)); u*;H$&
output.writeInt(nStartPos.length); Wm`*IBWA
for(int i=0;i<nStartPos.length;i++) )=d)j^t9
{ 7xv9v1['
// output.writeLong(nPos); jhQoBC>:
output.writeLong(fileSplitterFetch.nStartPos); *bf 5A9
output.writeLong(fileSplitterFetch.nEndPos); <{Y3}Q
} NRJp8G Z%U
output.close(); ]6[+tpx
} Qd kus214
catch(IOException e){e.printStackTrace ();} aG^E^^Y
catch(Exception e){e.printStackTrace ();} v9-4yZU^WR
} IPK1g3Z
7~XA92
vm_]X{80;
//读取保存的下载信息（文件指针位置） t_w\k_ T
private void read_nPos() -43>?m/a
{ B I)@n:p
try{ U364'O8_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); m^!j)\sM5
int nCount = input.readInt(); ufIvvZ*
nStartPos = new long[nCount]; BJWlx*U]
nEndPos = new long[nCount]; 9!Q ZuZY
for(int i=0;i<nStartPos.length;i++) (k #xF"yI
{ gmbRH5k
nStartPos = input.readLong(); 8]^|&"i.\d
nEndPos = input.readLong(); Wn+s:ov
} #eOHe4Vt
input.close(); anbw\yh8
} \f? K74
catch(IOException e){e.printStackTrace ();} `|?<KF164
catch(Exception e){e.printStackTrace ();} O5-GrR^yt
} U(y8nI]
W j^@Zq#
$j\>T@
private void processErrorCode(int nErrorCode) QrK%DN
{ UtTlJb{-j
System.err.println("Error Code : " + nErrorCode); CU\gx*=E
} {%u^O/M
`x/i1^/_@
x>Q% hl
//停止文件下载 5)T[ha77u
public void siteStop() [;Lgbgt3f
{ V<S6a
bStop = true; G&^8)S@1
for(int i=0;i<nStartPos.length;i++) <i</pA
fileSplitterFetch.splitterStop(); U@y)x+:
qzbW0AM[M
$.4A?,d
} \ opM}qZ
} e[u}Vf
//负责部分文件的抓取 TG$#aX\'
**FileSplitterFetch.java >"bW'
*/ yP+<kv4
package NetFox; <ytzGDx
zhs@YMY
5H XF3
import java.io.*; vRC >=y*=
import java.net.*; 5["3[h
5uQ+'*xN%
f;BY%$
public class FileSplitterFetch extends Thread { Y?J/KW3
p4f9v:b[
6R<+_e+v
String sURL; //File URL j}//e%$a
long nStartPos; //File Snippet Start Position ~9FL]qo
long nEndPos; //File Snippet End Position #z.n?d2Gd
int nThreadID; //Thread's ID S._2..%G
boolean bDownOver = false; //Downing is over 0l[52eZ/
boolean bStop = false; //Stop identical HL4=P,'
FileAccessI fileAccessI = null; //File Access interface 3pvqF,"~D
!;,\HvEZYw
-#9et30
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException x;yvv3-$
{ &Jj|+P-lY
this.sURL = sURL; +S0aA Wal
this.nStartPos = nStart; TS|Bz2(
this.nEndPos = nEnd; mP }<{oh`x
nThreadID = id; .cJoNl'q
fileAccessI = new FileAccessI(sName,nStartPos);//定位 U~?VN!<x[
} LJ~#0Zu?
B;(U?gC
1Y$%| `
public void run() uxD3+Q
{ Gh=I2GSo
while(nStartPos < nEndPos && !bStop) Jk(V ]
{ /Z:NoTGn
bl a`B=r
w6!97x
try{ AH&RabH2
URL url = new URL(sURL); 6H'A]0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r+C4<-dT
httpConnection.setRequestProperty("User-Agent","NetFox"); |8CxMs
String sProperty = "bytes="+nStartPos+"-"; %Hd[,duwO
httpConnection.setRequestProperty("RANGE",sProperty); Ez|NQ:o
Utility.log(sProperty); LEPLoF3,
*4%pXm;
EOu[X'gLr
InputStream input = httpConnection.getInputStream(); d%0Gsga}
//logResponseHead(httpConnection); q`r| DcN~
4Z%1eOR9V
/A,w{09G
byte[] b = new byte[1024]; 3S+9LOrhY
int nRead; PF/K&&9}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #)~u YQ
{ D(']k?
nStartPos += fileAccessI.write(b,0,nRead); bKsjbYuo
//if(nThreadID == 1) a`xAk^w+
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8]`#ax 5
} .c}+kHv
RR[zvH} E
*/IiL%g4u
Utility.log("Thread " + nThreadID + " is over!"); /_m)D;!y
bDownOver = true; ]$L5}pE3
//nPos = fileAccessI.write (b,0,nRead); (o B4*
} S=) c7t?a
catch(Exception e){e.printStackTrace ();} v%T'!(0j/
} a r8iuwfZ
} $?W2'Xm!V
q}L`8(a
5xdeuBEY8
//打印回应的头信息 4t(/F`
public void logResponseHead(HttpURLConnection con) hH5~T5?\
{ g?"QahHG
for(int i=1;;i++) 7!cLTq
{ \_,p@r]Q
String header=con.getHeaderFieldKey(i); TSewq4`K
if(header!=null) vc"!3x-G*
//responseHeaders.put(header,httpConnection.getHeaderField(header)); I9G^T' W
Utility.log(header+" : "+con.getHeaderField(header)); tIDN~[1
else :2nsi4
break; $T3_~7N
} *V',@NH#Os
} ni{'V4A
V:y6NfL7i'
,V!"4T,Z
public void splitterStop() 7u&l]NC?y
{ f:+/=MW
bStop = true; uc+{<E3,%
} q]OIP"yv
Ph""[0n%o
O>pX(DS L
} 4@fv%LOQo
.%n_{ab1
,==_u
/* #<[&Lw
**FileAccess.java !0?o3,of-
*//文件访问(定位，写) ^7+;XUyg
package NetFox; fdKE1,;
import java.io.*; +_fFRyu>
#d,)Qe[
KX9IC5pR
public class FileAccessI implements Serializable{ 7mYcO3{5{
Ll; v[Y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Jfr'OD2$ %
RandomAccessFile oSavedFile; nu+K N,3R"
long nPos; /xJD/"Y3&
w*XM*yJHU
4Pc-A
public FileAccessI() throws IOException wJ2cAX;"
{ nE8z1hBUq
this("",0); "|Q.{(|kO1
} VnW6$W?g
bdstxjJ`
:5/Ue,~ag
public FileAccessI(String sName,long nPos) throws IOException EF:ec9 .
{ BkB_?^Nv8
oSavedFile = new RandomAccessFile(sName,"rw"); M}[Q2v\
this.nPos = nPos; _f@,)n
oSavedFile.seek(nPos); sc+%v1Y#}
} 8a8a:d
k@lJ8(i^qU
\0 h>!u
public synchronized int write(byte[] b,int nStart,int nLen) 9Zl4NV&B
{ ;6PU
int n = -1; VI4mEq,V
try{ c>D~MCNxg
oSavedFile.write(b,nStart,nLen); u=InE|SH
n = nLen; ;&J>a8B$
} kl:/PM^
catch(IOException e) Ywhhs }f
{ qX\85dPn@}
e.printStackTrace (); VC/n}7p
} *Lrrl
m uO.
{2:baoG-
return n; ?aTH<
} nD/B:0'
5PeYQ-B|
TM6wjHFm
} 3_ J'+
p35)K5V
LAk .f
/* "W6cQsi
**SiteInfoBean.java ?9{^gW4|
*/ el5Pe{j'
package NetFox; GEy7Vb)
cwvJH&%0
5lHt~hB\
public class SiteInfoBean { 3HtM<su*h
I-!7 EC2{!
kIS )*_
private String sSiteURL; //Site's URL _-RqkRI
private String sFilePath; //Saved File's Path gWU#NRRc
private String sFileName; //Saved File's Name [VXQ&
private int nSplitter; //Count of Splited Downloading File Ao?b1VYy/
@xo8"kl
|GQq:MB;z
public SiteInfoBean() W gyRK2#!
{//nSplitter的缺省值为5 `?=3[
//default value of nSplitter is 5 bTeuOpp
this("","","",5); I(VqtC:K.
} axC{azo|
hJ8&OCR }
}\<=B%{
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *3Lo[GE>
{ ;q-c[TZC
sSiteURL= sURL; '{cND
sFilePath = sPath; ^jL)<y4`
sFileName = sName; ?qsLR
this.nSplitter = nSpiltter; hd'QMr[;
_Ml?cT/J.O
Ynf "g#(
} LkYcFD
aOg9Dqtg)f
a7_Q8iMe
public String getSSiteURL() r>8`gAhx
{ Y~*p27@fR
return sSiteURL; .&b^6$dC
} Hz,Gn9:p
GtmoFSZ
?84f\<"
public void setSSiteURL(String value) ~H\P0G5GA
{ hb8oq3*x
sSiteURL = value; /[Fk>Vhp
} ^3sv2wh^|8
?pJ2"/K
D#'CRJh;7
public String getSFilePath() $9\8?gS
{ HHw&BNQG
return sFilePath; gLt6u|0q
} {nSgiqd"28
Bkq4V$D_
%6lGRq{/?
public void setSFilePath(String value) YYI0iM>
{ uu]C;wl
sFilePath = value; k2->Z);X
} uYs45 G
4V[(RXc/
4mW$+lzn
public String getSFileName() ;FwUUKj
{ pR0!bgC
return sFileName; `Qb!W45
} )2EvZn
;/Y#ph[
kygj" @EX
public void setSFileName(String value) -TH(Z(pB
{ B7C<;`5TiD
sFileName = value; 0K"+u9D^
} i885T'
:twp95{R1
^0_>
public int getNSplitter() p\~ a=
{ A#q.)8
return nSplitter; lu>G=uCJ
} R+0fs$su
W)Y-^i5
#('R`~
public void setNSplitter(int nCount) 8yI4=P"F,
{ 6&E[hvu
nSplitter = nCount; ]Y?ZUSCJ
} -|#/KKF
} JK{2hr_a
,eOZv=:
z4J\BB
/* g;R
**Utility.java (`Y;U(n
*/ !2B~.!&
package NetFox; A][ ;v
r!{i2I|
dcemF
public class Utility { 7{"F%`7L
Z{ YuX
#l)o<Z
public Utility() wk'(g_DP
{ D)L~vA/8b
1A;,"8kBd
XH0Vs.w
} c;29GHs2
#WDpiV7B
//线程睡眠 o|84yT!~
public static void sleep(int nSecond) A0.xPru1p
{ ={h^X0<s9
try{ CO ZfR~}
Thread.sleep(nSecond); JeVbFZ8
} _^eA1}3
catch(Exception e) PCDvEbpG
{ 'q/C: Yo
e.printStackTrace (); hn6'$P
} ~tNk\Kkv
} ~P!=fU)
=<M>fJ)
//日志 o}wRgG
public static void log(String sMsg) [D?xd/G
{ %PR,TWe
System.err.println(sMsg); e7Gb7c~
} 9*"K+t:
Q.8^F
mT j
public static void log(int sMsg) |Cfo(]>G
{ |j8#n`'
System.err.println(sMsg); uRuu!{$
} UK8k`;^KI
} TFbF^Kd#:d
C]zgVbu
uuUjIZCtz
/* i7\>uni
**TestMethod.java Sxy3cv53
*/ (/> yfL]J
package NetFox; {c1wJ
Ym]rG 4
!"08TCc<
public class TestMethod { guy!/zQ>A
E[CvxVCx
Vhm^<I-d
public TestMethod() sdewz(xskj
{ ///xx/weblogic60b2_win.exe v<0S@9~
try{ +tlbO?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); nu|?F\o!
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >NpW$P{'
SiteFileFetch fileFetch = new SiteFileFetch(bean); @6U&7!
fileFetch.start(); 8,CL>*A
} 0eCjK.
catch(Exception e){e.printStackTrace ();} v!mP9c j
LXe'{W+bk
<dk9n}y<,
} hB:+_[=Kj.
G<*h,'B
,=%c e
public static void main(String[] args) [h\_yU[P
{ 7vH4}S\ q
new TestMethod(); .L]2g$W\p
} ;ov}%t>UD
} pAEJ=Te
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