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)); C]Y%dQh+a
} %o5'M^U
for(int i=0;i<nEndPos.length-1;i++) cyo[HI?WM
{ XFYa+]B2q
nEndPos = nStartPos[i+1]; C^;>HAK|F
} bp<,Xfl
nEndPos[nEndPos.length-1] = nFileLength; 3"juj'
} NeJ->x,
} 'E&tEbY
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wJD'q\n
//启动子线程 N<ux4tz
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,}O33BwJp
for(int i=0;i<nStartPos.length;i++) #m17cDL
{ {Kf5a m
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A{e>7Z72
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), qV;I<AM
nStartPos,nEndPos,i); 9J?lNq
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /EG'I{oC
fileSplitterFetch.start(); o".,JnbXl
} '4_c;](W
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8 /%{xB^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); w51l;2$des
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", U>OAtiq JX
nEndPos = " + nFileLength); I,<?Kv
// fileSplitterFetch[nPos.length-1].start(); =Z{jc
?J,,RK.
@meT8S9t
//等待子线程结束 2W2T
//int count = 0; TMo DN%{
//是否结束while循环 I$MlIz$l v
boolean breakWhile = false; yM7Iq)o6u
/!MVpi'6&
e`:^7$
while(!bStop) ,@/O\fit)
{ \|6VGh \Z
write_nPos(); {o 2 qY|S
Utility.sleep(500); w$Fg0JS
breakWhile = true; X&kp1Ih<^
K7([Gc9
jFJ}sX9]
for(int i=0;i<nStartPos.length;i++) U1HG{u,"y
{ D6H?*4f]
if(!fileSplitterFetch.bDownOver) $8xb|S[
{ p_(En4QSH
breakWhile = false; ]Vmo>
break; gO)":!_n W
} )$1>6C\
} CJER&"em7
if(breakWhile) a+cDH
break; lx=tOfj8
]%y>l j?Y
*c [^/
//count++; J8i,[,KcE
//if(count>4) !\[JWN@v
// siteStop(); d,?Tq
} d#]hqy
:vX%0|
Fi67"*gE
System.err.println("文件下载结束！"); ZX64kk+
} )UM^#<-
catch(Exception e){e.printStackTrace ();} Mn/@?K?y
} _Z!@#y@j
8#VD u(
i#hFpZ6u
//获得文件长度 ~!!\#IX
public long getFileSize() atF#0*e>
{ fBctG~CJH
int nFileLength = -1; b,YNCb]H
try{ 0#Lmajs
URL url = new URL(siteInfoBean.getSSiteURL()); *m^\&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); XL^05
httpConnection.setRequestProperty("User-Agent","NetFox"); vXRY/Zzj1
KyfH8Na?
6o7t eX
int responseCode=httpConnection.getResponseCode(); e).;;0
if(responseCode>=400) [!yA#{xl,
{ &e@)yVLL
processErrorCode(responseCode); 2jC`'8
return -2; //-2 represent access is error :>2wVN&\c
} >Rd~-w)!|
(/N&_r4x
q:TNf\/o
String sHeader; e1LIk1`p
Y}v3J(l
U31@++C[
for(int i=1;;i++) <K`E*IaW
{ j7gw?,
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); eu9*3'@A
//Utility.log(in.readLine()); 4$[o;t>
sHeader=httpConnection.getHeaderFieldKey(i); kI)}7e
if(sHeader!=null) vM6W64S
{ gWGDm~+
if(sHeader.equals("Content-Length")) C_kuW+H
{ } P ,"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); z&tC5]#
break; QJRnpN/
} sHc-xnd
} - ~|Gwr"
else %&yPl{
break; )\=xPfs
} {V2"Pym?
} *H/3xPh,*
catch(IOException e){e.printStackTrace ();} y'`/^>.
catch(Exception e){e.printStackTrace ();} '2*OrY
8zD>t~N2C
!43!JfD
Utility.log(nFileLength); l^9gFp~I
z'_Fg0kR{
qrYbc~jI7
return nFileLength; ^]nLE]M
} 7>__ fQu
o#e8 Piw
hc[ K VLpS
//保存下载信息（文件指针位置） ]*\MIz{56'
private void write_nPos() hj9TiH/+
{ &Y=0 0
try{ 14B',]`
output = new DataOutputStream(new FileOutputStream(tmpFile)); r!?ga
output.writeInt(nStartPos.length); (Z(S?`')
for(int i=0;i<nStartPos.length;i++) > 0MP[
{ Z|uvrFa
// output.writeLong(nPos); 3TF_$bd{
output.writeLong(fileSplitterFetch.nStartPos); p>`rTaeZg
output.writeLong(fileSplitterFetch.nEndPos); Iz09O:ER
} 1xW!j!A;
output.close(); <.QaOLD
} GXVx/)H
catch(IOException e){e.printStackTrace ();} *y?HaU
catch(Exception e){e.printStackTrace ();} #`*uX6C
} j#n ]q{s4
LJGpa)(
9kH~=`:?
//读取保存的下载信息（文件指针位置） u^tQ2&?O!P
private void read_nPos() 1+;bd'Ie
{ }}=n]_f
try{ !H\oQv-I
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); sv%X8
int nCount = input.readInt(); N|DI k
nStartPos = new long[nCount]; FfJp::|ddr
nEndPos = new long[nCount]; Qh1pX}X
for(int i=0;i<nStartPos.length;i++) "/aZ*mkjfJ
{ PN l/}'
nStartPos = input.readLong(); j2MA['{
nEndPos = input.readLong(); O8@65URKx
} 0Idek
input.close(); -[7+g
} ?ZlXh51
catch(IOException e){e.printStackTrace ();} h9H z6 >
catch(Exception e){e.printStackTrace ();} 4d@yAr}
} 5qtk#FB
K6IT$$g
.[O{,r
private void processErrorCode(int nErrorCode) 2`$*HPj+G
{ gT+g@\u[
System.err.println("Error Code : " + nErrorCode); A*y4<'}<
} 2d[q5p
L/tpT?$fi
V/ G1C^'/
//停止文件下载 73cb1kfPd
public void siteStop() [`\VgKeu
{ AOR?2u
bStop = true; j~-N2b6z
for(int i=0;i<nStartPos.length;i++) xSmG,}3mF
fileSplitterFetch.splitterStop(); k4K. mlIO
rFg$7
"`49m7q1H
} 'v6@5t19j
} UA6id|G
//负责部分文件的抓取 o8g7wM]M
**FileSplitterFetch.java .dlsiBh
*/ +;KUL6
package NetFox; VhUWws3E
hu}$\
e"S?qpJK
import java.io.*; 0Qt!w(
import java.net.*; R5uG.Oj-2
bw P=f.
,>a!CnK=
public class FileSplitterFetch extends Thread { loVg{N:
e'3V4iU]
="voJgvw
String sURL; //File URL Tz @=N]D
long nStartPos; //File Snippet Start Position J?8Mo=UZz
long nEndPos; //File Snippet End Position BIWe Hx
int nThreadID; //Thread's ID d+q],\"R
boolean bDownOver = false; //Downing is over duY?LJ@g
boolean bStop = false; //Stop identical {cXr!N^K
FileAccessI fileAccessI = null; //File Access interface &>JP.//spi
oP`l)`
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6'Q{xJe?
{ <L-F3Buu
this.sURL = sURL; x6UXd~ L e
this.nStartPos = nStart; SOOVUMj
this.nEndPos = nEnd; dR S:S_
nThreadID = id; _i05'_
fileAccessI = new FileAccessI(sName,nStartPos);//定位 PILpWhjL$9
} f$C{Z9_SX
EqW~K@
L kK *.
public void run() Ul}RT xJ
{ DSU8jnrL
while(nStartPos < nEndPos && !bStop) kUd]8Ff!
{ ;qWu8\T+
su%(!XJQpg
Z2g'&,uc#
try{ |.N[NY
URL url = new URL(sURL); d_!Z /M,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3`^@ymY
httpConnection.setRequestProperty("User-Agent","NetFox"); Y9)j1~
String sProperty = "bytes="+nStartPos+"-"; k*$WAOJEW
httpConnection.setRequestProperty("RANGE",sProperty); iOk;o=
Utility.log(sProperty); 8o~ NJ 6
l_h:S`z.
:ppaq
InputStream input = httpConnection.getInputStream(); I&1Lm)W&
//logResponseHead(httpConnection); YYe G9yR
P.]h`4
=^4Z]d
byte[] b = new byte[1024]; <V&0GAZ
int nRead; oYqHl1cs
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;,f\Wf"BW
{ ~|+ ~/
nStartPos += fileAccessI.write(b,0,nRead); #PkuCWm6
//if(nThreadID == 1) W@d&X+7e
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); QLd*f[n
} m!<HZvq?vf
N'`X:7fN
'ITq\1z
Utility.log("Thread " + nThreadID + " is over!"); Q~,Mzt"}W
bDownOver = true; P<PZ4hNx
//nPos = fileAccessI.write (b,0,nRead); sA2-3V<t8
} *] ihc u
catch(Exception e){e.printStackTrace ();} jWrU'X
} X)b$CG
} P[3i!"O>
=~1EpZ
r:H]`Uo'r
//打印回应的头信息 .&^p@A~
public void logResponseHead(HttpURLConnection con) S/]\GG{
{ gb_Y]U
for(int i=1;;i++) ,X@o@W+L
{ Uy?jVPL
String header=con.getHeaderFieldKey(i); j?K$w`
if(header!=null) yK*vn]}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _Sr}3
Utility.log(header+" : "+con.getHeaderField(header)); Geq]wv8
else l2 .S^S
break; `2.c=,S{
} QOWGQl%!
} Bj@>iw?g'
;R?@ D]
ER"69zQg|2
public void splitterStop() ofy"SM
{ =5|7S&{
bStop = true; p<fCGU
} TLwxP"
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Q %o@s3~O
} tsb[=W!Ar8
2*Qv6 :qK
~o'1PAW7
/* Gx C+lqH#
**FileAccess.java }5 rR^ryA
*//文件访问(定位，写) !5ps,+o
package NetFox; Os9SfL
import java.io.*; s)-oCT$[
TQ"XjbhU;X
` Ig5*X4|
public class FileAccessI implements Serializable{ FV^jCseZ
6`e{l+c=F
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7]VR)VAM
RandomAccessFile oSavedFile; )9eIo&Nl
long nPos; )-2Nc7
d/d)MoaJ*t
hP6f
public FileAccessI() throws IOException B;9,Qbb
{ !l[;,l
this("",0); F[ E'R.:
} '@{:FrG*U
io#}z4"'qY
MPB[~#:
public FileAccessI(String sName,long nPos) throws IOException 7b"fpB
{ | eBwcC#^
oSavedFile = new RandomAccessFile(sName,"rw"); `J.,dqGb
this.nPos = nPos; u^2`$W
oSavedFile.seek(nPos); alb3oipOB
} Y% iqSY
@O#!W]6NT6
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public synchronized int write(byte[] b,int nStart,int nLen) >_}isCd,
{ @|Pm%K`1
int n = -1; *;A ;)'
try{ D \ rns+
oSavedFile.write(b,nStart,nLen); |1@O>GG
n = nLen; j,YrM?Xdo
} ZLQmEF[>
catch(IOException e) !#0)`4O
{ j<^!"_G]*?
e.printStackTrace (); 5%,3)H{;t
} r^ r+h[V
_}R$h=YD
Z '5itN^
return n; k~[jk5te
} #49l\>1z
<9@n/
+#IUn
} $LXa]
B}"R@;N
i%i~qTN
/* opa/+V3E4
**SiteInfoBean.java yy3rh(ea
*/ I!/32* s1t
package NetFox; Ca |}i+
mb*Yw6q
s#$t!F??9
public class SiteInfoBean { {it.F4.
D6ZHvY8R
H!;N0",]N
private String sSiteURL; //Site's URL oG,>Pk
private String sFilePath; //Saved File's Path O,%UNjx9K
private String sFileName; //Saved File's Name mE~WE+lw9
private int nSplitter; //Count of Splited Downloading File y [Vd*8
+<E#_)}`D6
P'~`2W0sz
public SiteInfoBean() >2#<gp3
{//nSplitter的缺省值为5 er3Mvw
//default value of nSplitter is 5 6))":<J
this("","","",5); v`4w=!4
} ~n 'A1
I0 t#{i
HI5NWdfRl
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) t'_EcYNS
{ 2}^=NUM\NX
sSiteURL= sURL; t24`*'
sFilePath = sPath; Qa2h#0j
sFileName = sName; }IygU 6{G
this.nSplitter = nSpiltter; UBd+,]"f
'aNkU
FVXsu!R
} +yL;?+s>=
zgjg#|
;+75"=[YT
public String getSSiteURL() .X!!dx1<
{ S_7]_GQ9
return sSiteURL; CPZ{
} INndTF
*~8F.cx
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public void setSSiteURL(String value) Z}O]pm>=G
{ qGX@mo({
sSiteURL = value; h3F559bw/<
} $:s@nKgnD~
5AT^puL]]
s9C^Cy^su
public String getSFilePath() 0H_Ai=G
{ qT?{}I
return sFilePath; W*LC3B^
} t|@5,J
{t;o^pUF
&YIL As^8A
public void setSFilePath(String value) M~zI;:0O
{ O/eZ1YAC
sFilePath = value; ?;tPqOs&
} 2P:X_:`~[
->ZP.7
s8 WB!x{t
public String getSFileName() Y%i<~"k
{ 56C8)?
return sFileName; !$Uo$?gC
} ij]UAJ}t
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e"866vc,
public void setSFileName(String value) k_t|) J
{ aQoB1qd8
sFileName = value; Q7x[08TI
} {/noYB<;
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"'5(UiSFz
public int getNSplitter() hT^&*}G
{ C2<TR PT
return nSplitter; [60y.qE
} 7c_2.T@4
9swHa
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public void setNSplitter(int nCount) 10Eun }
{ XU7to]'K
nSplitter = nCount; J *LPv9)
} L\mF[Kd#+T
} ?EUg B\
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rQzdHA
/* O n0!>-b,
**Utility.java }/J"/ T
*/ RrxbsG1HP
package NetFox; jA"}\^%3
qz- tXc,
MXW1:
public class Utility { j~_iv~[
+aOevkY]
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public Utility() R.i]6H!
{ w*{{bISw|
W$]qo|2P
8K2@[TE=5
} lAnOO5@8
~;?mD/0k
//线程睡眠 v[|-`e*
public static void sleep(int nSecond) uWx<J3~q.
{ YXo?(T..
try{ +8<$vzB
Thread.sleep(nSecond); L)M{S3q,
} ((Av3{05H&
catch(Exception e) ta95]|z"j
{ 8i$|j~M a
e.printStackTrace (); l!gX-U%-
} `Fcr`[
} "(jD*\8x
T=/c0#Q|q
//日志 7a>+ma\
public static void log(String sMsg) :PV3J0pB~
{ xjBY6Ylz
System.err.println(sMsg); KsGW@Ho:
} In4VS:dD
7zzFM
%KF I~Qk
public static void log(int sMsg) }alq~jY
{ N?c~AEk9U
System.err.println(sMsg); <f (z\pi1
} 2aTq?ZR|8A
} NEIF1(:
@=G[mc\
(<B%Gy@
/* )z&C&Gqz
**TestMethod.java $@s-OQ}
*/ <:AA R2=
package NetFox; Y*b$^C%2
X\BFvSv8C
N5W!(h)
public class TestMethod { @u$NB3
R{[v#sF >#
pj7al;
public TestMethod() xjD$i'V+
{ ///xx/weblogic60b2_win.exe K:e[#b8:R
try{ S*n5d>;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5(2 C
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Tcv/EST
SiteFileFetch fileFetch = new SiteFileFetch(bean); tVf):}<h
fileFetch.start(); Vk`Uz1*
} 'uzHI@i
catch(Exception e){e.printStackTrace ();} Eve,*ATI
yOD=Vc7i
W)Mz1v #s
} =,6X_m
EPwU{*F
VI|2vV6?
public static void main(String[] args) )Ko~6.:5H
{ z(,j)".
new TestMethod(); D?dS/agA
} Lo}T%0"G
} rR^o
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