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)); ,#E3,bu6_4
} :$M9XZ~\
for(int i=0;i<nEndPos.length-1;i++) V6@*\+:3)
{ L9{mYA]q
nEndPos = nStartPos[i+1]; `qf\3JT\
} p|h.@do4
nEndPos[nEndPos.length-1] = nFileLength; GhG%>U#&a
} Sl. KLc@@
} BaWQ<T8p8
60hNCVq%
Q? <-`7
//启动子线程 ?qf:_G
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =E [4H
for(int i=0;i<nStartPos.length;i++) :(bdI]
{ 3{NaZIk
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DA+A >5/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Q$xa
nStartPos,nEndPos,i); Em~7D]Y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V17>j0Ev$W
fileSplitterFetch.start(); HF&h
} KjFZ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ig{A[7qN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); iUeV5cB
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", qs6Nb'JvQR
nEndPos = " + nFileLength); C2+{U
// fileSplitterFetch[nPos.length-1].start(); ?(5o@Xq
U6c)"^\
j>$=SMc
//等待子线程结束 pau*kMu^}
//int count = 0; vF9*tK'
//是否结束while循环 n9]IBIthe
boolean breakWhile = false; OLk9A
3)6+1Yc
tMxsR>sH
while(!bStop) F5FNhuC
{ 0hrCG3k.91
write_nPos(); 0V<Aub[${
Utility.sleep(500); x r-;,W
breakWhile = true; Np.no$_
ZB~l2
)ZT6:)
for(int i=0;i<nStartPos.length;i++) =dgo!k
{ ~A8qeaP
if(!fileSplitterFetch.bDownOver) D ?Nd;[
{ 4t&gW
breakWhile = false; >EBZ$X
break; 0n4g$JK7
} x`]Ofr'
} +<pVf%u5
if(breakWhile) nGq]$h
break; Ef2Yl
%*$5!;
{V}t'x`4c
//count++; wVx,JL5Jr
//if(count>4) =LlLE<X"%x
// siteStop(); ;M}itM
} H"#)&a7
1pd 9s8CA
ooTc/QEYi
System.err.println("文件下载结束！"); pTcbq
} *-?Wcz
catch(Exception e){e.printStackTrace ();} EfFz7j&X
} Yuwc$Qp)
~c9>Nr9|`
j(0Ilx|7v
//获得文件长度 cwk+#ur
public long getFileSize() uzHT.iBn
{ YSqv86
int nFileLength = -1; w?kGi>7E
try{ [dl+:P:zc
URL url = new URL(siteInfoBean.getSSiteURL()); x|.v{tQa
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mfZ)^X
httpConnection.setRequestProperty("User-Agent","NetFox"); HwB {8S?sm
znt)]>f#
?Fce!J
int responseCode=httpConnection.getResponseCode(); k) "ao2iXL
if(responseCode>=400) 9z #P
{ RG&I\DTyt
processErrorCode(responseCode); `-4'/~G
return -2; //-2 represent access is error [-4KY4R
} K'x4l,rq
`q%U{IR
y|^EGnaE
String sHeader; 8s<^]sFP
Ks#A<! ;=
zm3-C%:Bw
for(int i=1;;i++) \,2gTi,=
{ w"{bp
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &B}Lo
//Utility.log(in.readLine()); >L^xlm%7o
sHeader=httpConnection.getHeaderFieldKey(i); |z:Q(d06
if(sHeader!=null) q7|:^#{av
{ #;`Oj
if(sHeader.equals("Content-Length")) 27m@|M] R
{ C`)_i3 ^
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); @cZ\*,T
break; fb23J|"
} t\zbEN
} u+m4!`
else md?b*
break; 0x\2#i
} 7!pLK&_
} (qUK7$
catch(IOException e){e.printStackTrace ();} cQX:%Ix=
catch(Exception e){e.printStackTrace ();} }g>kpa0c
Y=E9zUF
Rv,82iEKs
Utility.log(nFileLength); qYK4)JP
@M=$qO_$9
!x7o|l|cP
return nFileLength; (VyA6a8
} T'.[F
rIVvO
)Ob]T{GY
//保存下载信息（文件指针位置） 3E,DipHg
private void write_nPos() FqwIJ|ct
{ \ZMP_UU(
try{ Z ] '>
output = new DataOutputStream(new FileOutputStream(tmpFile)); r?pZ72q
output.writeInt(nStartPos.length); 1SUzzlRx
for(int i=0;i<nStartPos.length;i++) ll%G!VR
{ sm
// output.writeLong(nPos); P[FV2R~
output.writeLong(fileSplitterFetch.nStartPos); jJia.#.Ze
output.writeLong(fileSplitterFetch.nEndPos); qz`rL#W]
} ZYa\"zp-
output.close(); G=|70pxU
} :k~dj C
catch(IOException e){e.printStackTrace ();} :=9<
catch(Exception e){e.printStackTrace ();} tw<P)V\h
} /g@^H/DO
K\(6rS}N
7(Cx!Yb
//读取保存的下载信息（文件指针位置） V.8%|-d
private void read_nPos() vM(Xip7
{ 3rNc1\a;
try{ T`\]!>eb
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); L+.H z&*@
int nCount = input.readInt(); M\9F:.t=
nStartPos = new long[nCount]; I^G^J M!
nEndPos = new long[nCount]; h=6xZuA\
for(int i=0;i<nStartPos.length;i++) F+ukAT
{ Q_]~0PoH
nStartPos = input.readLong(); Ux}W&K/?'
nEndPos = input.readLong(); |gv{z"
} Efx=T$%^&
input.close(); FaY_0G;y
} \0?$wIH?
catch(IOException e){e.printStackTrace ();} 3+>OGwfQ
catch(Exception e){e.printStackTrace ();} a8Uk[^5
} J4>;[\%m
|@RpWp>2
1`JB)9P
private void processErrorCode(int nErrorCode) u1^\MVO8
{ ?YBaO,G9o
System.err.println("Error Code : " + nErrorCode); ]g,lRG
} J\=a gQ
Xwq]f:@V
j;\[pg MR/
//停止文件下载 Ie@Jb{x
public void siteStop() !n<o)DsZR
{ E(4w5=8TI
bStop = true; uv]{1S{tb
for(int i=0;i<nStartPos.length;i++) ?#BV+#(
fileSplitterFetch.splitterStop(); \|%E%Yc
OCNPi4
BvK QlT
} fx)KNm8Lx
} ?:igumeYX
//负责部分文件的抓取 E'EcP4eL
**FileSplitterFetch.java Wp[9beI*M
*/ ar$*a>'?
package NetFox; ?pG/m%[
=45W\
kRlA4h1u_$
import java.io.*; q]FBl}nwl%
import java.net.*; 3-|3`(
=6\LIbO
OJ1tV% E
public class FileSplitterFetch extends Thread { h5GU9M
zvO:"w}
P:k+ y$
String sURL; //File URL <a|@t@R
long nStartPos; //File Snippet Start Position 8lP6-VA
long nEndPos; //File Snippet End Position L:@fP~Erh
int nThreadID; //Thread's ID {@.Vh]
boolean bDownOver = false; //Downing is over G1d(,4Xp
boolean bStop = false; //Stop identical bL1m'^r
FileAccessI fileAccessI = null; //File Access interface VagT_D
66\jV6eH7L
+Gh7^v|"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Qxa{UQh}9
{ 6B6vP%H#
this.sURL = sURL; |PP.<ce\-
this.nStartPos = nStart; N3%*7{X 9
this.nEndPos = nEnd; q0./O|Dj
nThreadID = id; .H~YI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7\Fs=\2l+'
} 0L#/lDNk
fS=hpL6]@
O{]9hm(tN
public void run() JOD/Raq.1k
{ Ig \#f
while(nStartPos < nEndPos && !bStop) E[g*O5
{ QlEd6^&
38IMxd9v
{mTytT
try{ 42+#<U7T
URL url = new URL(sURL); A.En+-[\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); QDTNx!WL
httpConnection.setRequestProperty("User-Agent","NetFox"); Kq)MTlP0g
String sProperty = "bytes="+nStartPos+"-"; I#G0, &Gv
httpConnection.setRequestProperty("RANGE",sProperty); Eu,`7iQ?(
Utility.log(sProperty); pqR\>d0
3BQ!qO17^d
nxo+?:**
InputStream input = httpConnection.getInputStream(); ?LP9iY${
//logResponseHead(httpConnection); u:dx;*
d@ Ja}`
|E3X
byte[] b = new byte[1024]; :/N+;- 18
int nRead; /*rhtrS)
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) QHlU|dR)Ry
{ #hw>tA6
nStartPos += fileAccessI.write(b,0,nRead); d~9!,6XM
//if(nThreadID == 1) Z(GfK0vU
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W|5_$p
} Um.qRZ?
ae+*=,
yj_4gxJ\
Utility.log("Thread " + nThreadID + " is over!"); o{WyQ&2N
bDownOver = true; n<7q`tM#
//nPos = fileAccessI.write (b,0,nRead); v)X\GmW7w
} W+=o&V
catch(Exception e){e.printStackTrace ();} *d*,Hqn
} hdma=KqZ(
} <q2?S
(k?7:h
oBQm05x"
//打印回应的头信息 ZH 6\><My
public void logResponseHead(HttpURLConnection con) l.+yn91%>
{ 3V<&|
for(int i=1;;i++) L{fFC%|l2L
{ Hi}RZMr1
String header=con.getHeaderFieldKey(i); $E!J:Y=
if(header!=null) j\&pej
//responseHeaders.put(header,httpConnection.getHeaderField(header)); # Su~`]
Utility.log(header+" : "+con.getHeaderField(header)); Zjh2{ :
else cr;`Tl~}s
break; +^|iZbZKx
} aSutM
} 0<p{BL8
R.9V,R5
j2 %^qL
public void splitterStop() \cJa;WM>
{ PkuTg";
bStop = true; (5Nv8H8|
} >SbK.Q@ei
)Kd%\PP
na+d;h*~y
} 9i q""
#]Y>KX2HG
mN_Z7n;^eh
/* c3TKl/
**FileAccess.java G&f8n
*//文件访问(定位，写) 4Y\wnwI
package NetFox; <n"C,
import java.io.*; Nf41ZT~
""iaGH+Cxw
IH*s8tPc
public class FileAccessI implements Serializable{ K4ZolWbU
eOT+'[3"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 s%4M$e
RandomAccessFile oSavedFile; RW'nUL?_\
long nPos; /iaf ^ >
C~% 1w%nn
s#9Ui#[=h
public FileAccessI() throws IOException SGL|Ck
{ [{u(C!7L`
this("",0); ?#A]{l
} 8hanzwoJ:
V~IIYB7
f9$xk|2g
public FileAccessI(String sName,long nPos) throws IOException +j14Q$
{ !~i' -4]
oSavedFile = new RandomAccessFile(sName,"rw"); Z~
this.nPos = nPos; 4'1m4Ugg
oSavedFile.seek(nPos); /b#l^x:j
} Ta=s:trP
@@G6p($
-e GL)M
public synchronized int write(byte[] b,int nStart,int nLen) W!Gdf^Yy<
{ (.Y/
int n = -1; rh*sbZ68>E
try{ 1Tp/MV/>
oSavedFile.write(b,nStart,nLen); $g9**b@
n = nLen; }n:?7
} >R,'5:Rw
catch(IOException e) U&Wwyu:4i
{ pmvT$;7I
e.printStackTrace (); ^"\s eS
} 8)*2@-Rp
)j l8!O7
VSX@e|Nj
return n; K6JVg$
} ] ]U<UJ
W*DVi_\$y
=<@2#E)
} !|waK~jK
?4H#G)F
Z6C=T;w
/* @oP_;G
**SiteInfoBean.java #65^w=Sp}
*/ CbBSFKM
package NetFox; e>rRTN
wBj-m
2|iV,uJ&
public class SiteInfoBean { \2-@'^i
N;oQ^B'
xiF7}]d+
private String sSiteURL; //Site's URL k,F"-K+M
private String sFilePath; //Saved File's Path POI.]1i
private String sFileName; //Saved File's Name :,12")N
private int nSplitter; //Count of Splited Downloading File ] Wy)
Psura$:
u9woEe?
public SiteInfoBean() Jq.lT(E8D
{//nSplitter的缺省值为5 O=cxNy-I
//default value of nSplitter is 5 u6V/JI}g
this("","","",5); MB ju![n
} j1q[2'
s.Y4pWd5@
cLa]D[H
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) pL=d% m.W
{ mMx;yZ
sSiteURL= sURL; !rDdd%Z
sFilePath = sPath; D%mXA70
sFileName = sName; W1Lr_z6
this.nSplitter = nSpiltter; +6$g!S5{
8(g:HR*;
v44}%$
} r[(xjn
Lf([dE1
G0 J4O!3
public String getSSiteURL() c !ZM
{ yq-=],h
return sSiteURL; 5RH2"*8T
} k#Of]mXXz
9Ya<My
keW~ NM
public void setSSiteURL(String value) PP~rn fE
{ 0_P}z3(M
sSiteURL = value; anw}w!@U
} #PDf,^
HjqB^|z
,B(7\
public String getSFilePath() /iNa'W5\
{ >SN|?|2U/
return sFilePath; 9Etz:?)b
} iI@jZVk
02`$OTKz
.#u_#=g?
public void setSFilePath(String value) )Au6Nf
{ "vCM}F
sFilePath = value; s5.AW8X=?*
} 5ercD
!MDNE*_
)D'^3)FF
public String getSFileName() u<q :$
{ X8dR+xd
return sFileName; +;g{$da5
} JjpRHw8\
CM)Q&:
g*)K/Z0pJ$
public void setSFileName(String value) u~ ~R9.
{ M/?KV9Xk2
sFileName = value; 9odJr]
} RCTQhTy=
v%k9M{
N"/-0(9[
public int getNSplitter() 8zLY6@
{ !Fw?H3X!"q
return nSplitter; `b8v1Os^2
} +')f6P;t>=
=cN&A_L(
Y={&5Mir
public void setNSplitter(int nCount) RjF'x
{ QIN."&qC^
nSplitter = nCount; ri`R<l8
} $@d9<83=
} wiaX&-c]8
IM$2VlC
w{~+EolK
/* ms($9Lv/
**Utility.java PiV7*F4qI.
*/ n9pN6,o+
package NetFox; 1Gt/Tq$_b
<PPNhf8
I/VxZ8T
public class Utility { D'Z|}(d&
lnovykR
;U1UFqZ`
public Utility() kyAXRwzI
{ O3N0YGhJ
I$Qs;- (
5qg2Zc~
} +jg9$e"
JOjoiA
//线程睡眠 5Zmw} M
public static void sleep(int nSecond) oLWJm
{ i{!T&8
try{ xD&^j$Em
Thread.sleep(nSecond); Lb{e,JH
} *Ype>x{
catch(Exception e) @)kO=E d
{ DjU9 uZT
e.printStackTrace (); SVjl~U-^
} Xi?b]Z
} pE{yv1Yg
)$w*V9d
//日志 r'CM
public static void log(String sMsg) r1ws1 rr=
{ 9Rm/V5
System.err.println(sMsg); f<+4rHT
} bX.ja;;
@i^~0A#q*
p^(&qk?ut
public static void log(int sMsg) Hk>79};
{ 2=?tJ2E
System.err.println(sMsg); ^:9$@+a
} 0Io'bF
} .nYUL>
#jAqra._b
UgWs{y2SE.
/* nR4y`oP+
**TestMethod.java :{NC-%4o0
*/ f84:hXo6
package NetFox; 5XuT={o
LlBN-9p
liR?
public class TestMethod { C^QtSha
`/Nm 2K
yq+!czlZ
public TestMethod() Z/^ u
{ ///xx/weblogic60b2_win.exe e]=!"nJ+
try{ 1!pa;$L
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "NRDNqj(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !6Sd(2
SiteFileFetch fileFetch = new SiteFileFetch(bean); !*2%"H*
fileFetch.start(); dd?x(,"A`
} ;q0uE:^S
catch(Exception e){e.printStackTrace ();} {lth+{&L#
`mye}L2I
CG'.:`t
} lpH=2l$>?
T#pk]c6Q
`%3/
public static void main(String[] args) DK0.R]&4(
{ 7bxA]s{m
new TestMethod(); \A`hj~
} gyS+9)gY
} X(jVRr_m9
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