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)); H&*&n}vh5y
} I&15[:b=-
for(int i=0;i<nEndPos.length-1;i++) ,ynN801\m
{ lgVT~v{U`n
nEndPos = nStartPos[i+1]; T7ShE-X
} ;9)nG,P3
nEndPos[nEndPos.length-1] = nFileLength; fuHNsrNlm
} S`mB1(h
} C<:wSS^@1
D8w.r"ne
?\4kV*/Cqz
//启动子线程 $Nvox<d0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )2W7>PY
for(int i=0;i<nStartPos.length;i++) -u~:Gd*l0
{ ?S=y>b9R
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :+9. v
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), k "7,-0gz
nStartPos,nEndPos,i); d/oD]aAEr
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h8.(Q`tli
fileSplitterFetch.start(); 0nI*9
} `3[W~Cq
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), py~[M'p(H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); f9_Pn'"I
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !T)_(}|6}
nEndPos = " + nFileLength); A;ZluQ
// fileSplitterFetch[nPos.length-1].start(); OBlQ
$M-"az]
rFC9y o
//等待子线程结束 23=wz%tF
//int count = 0; \[]BB5)8
//是否结束while循环 E<B/5g!
boolean breakWhile = false; m#Z9wf] F
$@{d\@U
B[w.8e5
while(!bStop) 'dQGb-<_<
{ $i8oLSRV
write_nPos(); It3@ Cd>
Utility.sleep(500); mDwuJf8}
breakWhile = true; 8EiS\$O-
P%[{ 'u
BB1_EdoG
for(int i=0;i<nStartPos.length;i++) 2^5RQl/
{ s&WE'
if(!fileSplitterFetch.bDownOver) Qd3ppJn
{ 3M[d6@a
breakWhile = false; SJ8 ~:"\P
break; lnMU5[g{
} ="@f~~
} HCktgL:E=
if(breakWhile) c0jTQMe4yl
break; [ot+EA
-ImO y|
FDGzh/
//count++; XI ><;#
//if(count>4) u[wDOw
// siteStop(); ZZxt90YR'5
} QRdtr
z:Ru`
A5}N[|z
System.err.println("文件下载结束！"); ==KDr0|G
} ;L],i<F
catch(Exception e){e.printStackTrace ();} Y?oeP^V'u
} 2I=4l
ms&5Bq+9
KxJDAP
//获得文件长度 LsMq&a-j2
public long getFileSize() WT 5 2
{ n%vmo f
int nFileLength = -1; "0>AefFd#
try{ |U~\;m@
URL url = new URL(siteInfoBean.getSSiteURL()); &u2m6 r>W
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GIkVU6Q}
httpConnection.setRequestProperty("User-Agent","NetFox"); '|%\QWuZ
~-yq,x
z^KBV^n
int responseCode=httpConnection.getResponseCode(); FVOPC:}bj
if(responseCode>=400) aNICSxDN
{ (w<llb`]
processErrorCode(responseCode); 70R_O&f-k
return -2; //-2 represent access is error UY\E uA9
} +OInf_O
o|s|Wmx>u
8RZqoQDH
String sHeader; }&l%>P
dZd]p8
?|hYtV
for(int i=1;;i++) [].euDrX
{ K9RRY,JB
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )DQcf]I
//Utility.log(in.readLine()); A(C0/|#V
sHeader=httpConnection.getHeaderFieldKey(i); +I.{y
if(sHeader!=null) ,}^;q58
{ _4lKd`
if(sHeader.equals("Content-Length")) ? a*yK8S
{ @C~gU@F
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9~r8$,e
break; ``h*A
} w/ID yQ
} Jd|E 4h~(
else <5|:QLqy
break; '_n$xfH
} 0e'@Xo2e
} k <LFH(
catch(IOException e){e.printStackTrace ();} 7X/B9Hee
catch(Exception e){e.printStackTrace ();} x)kp*^/
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sdQ"[`~2R
Utility.log(nFileLength); +'g~3A-G
-0*z"a9<p8
3qp\jh=FE
return nFileLength; ^7`gf
} p"Di;3!y!
.Jc<Gg
Is ( Ji
//保存下载信息（文件指针位置） Ez^wK~
private void write_nPos() Q"GZh.m
{ ML1/1GK*i+
try{ R8, g^N
output = new DataOutputStream(new FileOutputStream(tmpFile)); m8*)@e
output.writeInt(nStartPos.length); N<HJ}geC"
for(int i=0;i<nStartPos.length;i++) Pfg.'Bl
{ [:{HX U7y
// output.writeLong(nPos); @PKY>58)
output.writeLong(fileSplitterFetch.nStartPos); bqZ5GKUo
output.writeLong(fileSplitterFetch.nEndPos); [_tBv" z
} a7fn{VU8
output.close(); w"h3e
} KD..X~Me
catch(IOException e){e.printStackTrace ();} =|3*Y0
catch(Exception e){e.printStackTrace ();} T$Rf
} c38ENf
}}d,xI
yt`K^07@
//读取保存的下载信息（文件指针位置） $?|$uMIafp
private void read_nPos() tNDv[IF
{ srIt_Wq
try{ >yt8gw0J
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); vq5o?$:-
int nCount = input.readInt(); ";w"dfC^
nStartPos = new long[nCount]; (5=B^9{R
nEndPos = new long[nCount]; _Qf310oONS
for(int i=0;i<nStartPos.length;i++) Y$eO:67;
{ lMb&F[KJ7
nStartPos = input.readLong(); SOJkeN
nEndPos = input.readLong(); mA\}zLw+r9
} WQltUaF
input.close(); ggzcANCD<
} @VKN6yHH
catch(IOException e){e.printStackTrace ();} B d?{ldg
catch(Exception e){e.printStackTrace ();} lD1m<AC
} <L<d_
5wm(gF_t
&jE@i#
private void processErrorCode(int nErrorCode) FWQNO(
{ `z6I][Uf
System.err.println("Error Code : " + nErrorCode); bb`8YF+?'
} a~Y`N73/c
,\ zx4*
d01]5'f?o
//停止文件下载 YyD0g9{
public void siteStop() t|}}#Z!I[f
{ pn aSOyR
bStop = true; !s[[X5
for(int i=0;i<nStartPos.length;i++) iiTt{ab\Y
fileSplitterFetch.splitterStop(); JR4fJG
:z%q09.)
%1kIaYZ
} <2fgao&-n
} 7NQEnAl
//负责部分文件的抓取 yo!Y%9
**FileSplitterFetch.java kuo!}QFL
*/ rc7^~S]5
package NetFox; *L#\#nh7
AP/#?
PI$K+}E
import java.io.*; ->a|
import java.net.*; Ox&]{
qPgny/(
{*K7P>&
public class FileSplitterFetch extends Thread { :#Nrypsu
Nu7lPEM
4)E$. F^
String sURL; //File URL g,}_&+q:.M
long nStartPos; //File Snippet Start Position +Z=DvKsTJ
long nEndPos; //File Snippet End Position 'Em633
int nThreadID; //Thread's ID )PjU=@$lI
boolean bDownOver = false; //Downing is over nm]m!.$d
boolean bStop = false; //Stop identical s73'h
FileAccessI fileAccessI = null; //File Access interface em?Q4t
L}pj+xB
c4(og|ifk
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException trMwFpfu
{ `-w;/A"MJ
this.sURL = sURL; CsiRM8
this.nStartPos = nStart; H[U"eS."
this.nEndPos = nEnd; NWII?X#T}
nThreadID = id; L_R(K89w
fileAccessI = new FileAccessI(sName,nStartPos);//定位 o'|B|oZ
} DN;3VT.-
z?'z{+HY
V&J'2Lq
public void run() i&\cDQ 3
{ ..UA*#%1
while(nStartPos < nEndPos && !bStop) b-HELS`nX
{ C,VvbB
E5g|*M.+f
&ZI-#(P
try{ U*7x81v?j
URL url = new URL(sURL); |?4NlB6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "WzD+<oL
httpConnection.setRequestProperty("User-Agent","NetFox"); -nDY3$U/
String sProperty = "bytes="+nStartPos+"-"; b>L?0p$ej
httpConnection.setRequestProperty("RANGE",sProperty); r&Qq,koE
Utility.log(sProperty); V3q[$~9
tYMPqP,1.
7,5Bur
InputStream input = httpConnection.getInputStream(); N%!{n7`N:
//logResponseHead(httpConnection); FPukV^
F $1f8U8
EjP9/VG@=
byte[] b = new byte[1024]; l9f%?<2D
int nRead; |H>;a@2d
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5Tq*]ZE
{ {_~vf
nStartPos += fileAccessI.write(b,0,nRead); ayQ2#9X}
//if(nThreadID == 1) 'C) v?!19
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *g[MGyF"
} %{&,5|8
&6nLnMF8x
nfksi``Vq
Utility.log("Thread " + nThreadID + " is over!"); hd@jm^k
bDownOver = true; 3>mAZZL5[
//nPos = fileAccessI.write (b,0,nRead); CI^s~M >
} >Et~h65d5
catch(Exception e){e.printStackTrace ();} f-Zi!AGh>
} h}4yz96WD
} K>G.HN@
h`f$]_c
x.Tulo0/
//打印回应的头信息 y'(a:.%I
public void logResponseHead(HttpURLConnection con) VE?Aa
{ $0|`h)&
for(int i=1;;i++) ]EqwDw4
{ ji.T7wn1u
String header=con.getHeaderFieldKey(i); 5:(/k\9+yv
if(header!=null) "<&) G{
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 6o4Y]C2W{1
Utility.log(header+" : "+con.getHeaderField(header)); BJKv9x1jK
else DGNn#DP
break; P=R-1V
} zJov*^T-C
} yX/{eX5dr
zZ;V9KM>v
&pW2R}
public void splitterStop() lN*beOj
{ 5}Z>N,4
bStop = true; fGoJP[ae
} wU|jw(
`RXlqj#u
k%VYAON
} p4D.nB8
{@hJPK8
RoNE7|gF:
/* 6B+?X5-6DH
**FileAccess.java D~n-;T
*//文件访问(定位，写) d .%2QkL
package NetFox; /QT>"
import java.io.*; _ Y7Um
g)7@EU2
Z"$iB-]
public class FileAccessI implements Serializable{ T"1=/r$Ft
X.ecA`0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [,(+r7aB
RandomAccessFile oSavedFile; n;wViw
long nPos; Q" r y@ (I
wHh6y?g\
8Oz9 UcG
public FileAccessI() throws IOException 6Ta+f3V
{ xxA^A
this("",0); w|abaMam
} 7^tYtMm|U
YdyTt5-
WtO@Kf:3GH
public FileAccessI(String sName,long nPos) throws IOException ~RLWr.pK
{ @0(%ayi2Y
oSavedFile = new RandomAccessFile(sName,"rw"); y?U@F/^}N
this.nPos = nPos; FC WF$'cO
oSavedFile.seek(nPos); dh9@3. t
} #}l$<7ZU
_}F_Q5)
}QBL{\E!
public synchronized int write(byte[] b,int nStart,int nLen) Xk\IO0GF
{ uh`5:V
int n = -1; Swh\^/B8
try{ E\TWPV'/
oSavedFile.write(b,nStart,nLen); q3C
n = nLen; 4U~'Oa@p
} <KfR)7I$0a
catch(IOException e) ?d+ri
{ [5tvdW6Z&
e.printStackTrace (); A1r%cs
} %J Jp/I
`vz7}TY
g)=$zXWhP
return n; bg|dV
} Ve${g`7&
a,(nf1@5
TO.STK`
} maeQ'Sv_&
oY0*2~sg
A@9\Qd
/* c91^7@Xv
**SiteInfoBean.java %|D)U>o{
*/ Zu2`IzrG#
package NetFox; JY@bD:
vG7Mk8mIr
1rs.
public class SiteInfoBean { :!hO9ho
<B>hvuCoH
p3Ozfk
private String sSiteURL; //Site's URL -<9Qez)y
private String sFilePath; //Saved File's Path {~w(pAx
private String sFileName; //Saved File's Name h(R7y@mp\0
private int nSplitter; //Count of Splited Downloading File fDqDU
HEAW](s
%8wBZ~1-
public SiteInfoBean() $-u c#57
{//nSplitter的缺省值为5 %|ClYr
//default value of nSplitter is 5 'HJ+)[0X*
this("","","",5); v 2p
} p(nO~I2E
TspX7<6r
Na@;F{
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) bI|{TKKN&P
{ *JfGGI_E
sSiteURL= sURL; L>mM6$l
sFilePath = sPath; v9FR
sFileName = sName; ,]nRnI^
this.nSplitter = nSpiltter; :y`LF<
\F-n}Z
4f~sRubK
} DaJ,(DJY
<T;V9(66
*C0a,G4
public String getSSiteURL() 8EMBqhl
{ lJN#_V0qW
return sSiteURL; dNY'uv&Y
} Thu_`QP^
U;IGV~oT
$MGKGWx@E
public void setSSiteURL(String value) ,X1M!'
{ (X-( WMsqQ
sSiteURL = value; rk4KAX_[
} ;Z`a[\i':
jMCd`Q]K
q,<l3rIn
public String getSFilePath() 6rj iZ%
{ xf/K+
return sFilePath; .AOc$Nt
} mtkZF{3Jx
M$Ui=GGq
]kx<aQ^
public void setSFilePath(String value) ']fyD3N
{ S.Kcb=;"L
sFilePath = value; 'jMs&
} )/JVp>
] Ok &%-
}!k?.(hpE
public String getSFileName() 9H;Os:"\|
{ *3E3,c8{A
return sFileName; [W{|94q
} X Db%-
kTfRm^
n0gjcDHQ
public void setSFileName(String value) -?:8sv*X
{ 1Az&BZU[
sFileName = value; 5+!yXkE^e
} Pv,PS.,-
j>?nL~{
u{&=$[;
public int getNSplitter() lK7:qo
{ }~=<7|N.
return nSplitter; @%2crJnkS
} F):kF_ho
$H.U ~
WRkuPj2
public void setNSplitter(int nCount) W( sit;O
{ BeQ'\#q,
nSplitter = nCount; Ix,b-C~
} N0}[&rE 8
} "%+||IyW
4[gbRn'
": BZZ\!
/* Sin)]zG~0
**Utility.java r}e(MT:R'
*/ -6uLww=w4
package NetFox; 9<y{:{i
l l*g *zt3
[tSv{
public class Utility { eN|zD?ba&
\'u+iB g
3I)oqS@q'
public Utility() I4w``""c
{ %%n&z6w-
Fje /;p
## vP(M$
} .pe.K3G&
42hG}Gt
//线程睡眠 f%t N2k
public static void sleep(int nSecond) 9[*P`*&
{ ZVJ6 {DS/
try{ "QS(4yw?jg
Thread.sleep(nSecond); g8&& W_BI
} \24'iYtqW
catch(Exception e) }id)~h_@
{ )BI%cD
e.printStackTrace (); .Jg<H %%f
} n#WOIweInf
} {wt9/IlG1
N4-Y0BO
//日志 .Wp(@l'Hd
public static void log(String sMsg) |B$JX'_
{ *gGw/jA/
System.err.println(sMsg); ^/Yk*Ny
} ^t<L
rfQs 7S;G
g0a!auWM
public static void log(int sMsg) s nxwe
{ v,N!cp1
System.err.println(sMsg); NcwUK\
} "30=!k
} [:e>FXV
y6sY?uu
Yz0HBEA
/* bT9:9LP
**TestMethod.java rO#$SW$YW
*/ y,Bj,zw
package NetFox; 9"1=um=
gMq;
,g?M[(wtc
public class TestMethod { 0e]J2>
>b3IZ^SB#$
{[NQD3=+F
public TestMethod() 1yU!rEH
{ ///xx/weblogic60b2_win.exe OEbZs-:
try{ tVX|e2Y
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); n31nORx50
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); L:lnm9<
SiteFileFetch fileFetch = new SiteFileFetch(bean); m|+zMf&
fileFetch.start(); b+ZaZ\-y |
} iK'A m.o+
catch(Exception e){e.printStackTrace ();} kaR55
p>pAU$k{O
s%>u[-9U
} "].TKF#yg
j9RpYz
z=jzr=lP
public static void main(String[] args) j`3IizN2
{ >B;S;_5=
new TestMethod(); aa!1w93?i
} ko!aX;K
} _Bn8i(
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