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)); $tz;<M7B
} )_{dWf1
for(int i=0;i<nEndPos.length-1;i++) ulu9'ch
{ /E Bo3`
nEndPos = nStartPos[i+1]; 7w 37S
} f:ZAG4B
nEndPos[nEndPos.length-1] = nFileLength; ?g?L3vRK
} )\sc83L
} hy}8Aji&
kjEEuEv
_$= _du
//启动子线程 .gG1kWA-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; SGh1 DB
for(int i=0;i<nStartPos.length;i++) [!}:KD2yX
{ M>&%(4K
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A:aE|v/T&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), B+[A]dgS
nStartPos,nEndPos,i); /GIxR6i
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^\\Tx*#i
fileSplitterFetch.start(); GKvN* SU=
} qY~`8 x
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =0^Ruh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); HFwN
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", BDVHol*g
nEndPos = " + nFileLength); m-H-6`]
// fileSplitterFetch[nPos.length-1].start(); 9;Itqe{8w
Gqcq,_?gt
!,[C]Q1
//等待子线程结束 Vnx,5E&
//int count = 0; ?"zY"*>4
//是否结束while循环 RQ'exc2x0
boolean breakWhile = false; 6:q"l\n>
h.-@ F
~.A)bp
while(!bStop) Hu.t 3:w
{ ]4h92\\965
write_nPos(); SV:4GVf
Utility.sleep(500); ox:[f9.5
breakWhile = true; +x_Rfk$fb
{.Z}5K
5WC+guK7
for(int i=0;i<nStartPos.length;i++) [|P!{?A43|
{ SG-'R1 J
if(!fileSplitterFetch.bDownOver) }:u~K;O87
{ FL(6?8zK
breakWhile = false; (S xR`QP?,
break; vFE;D@bz:
} ta`N8vnf
} $-#Yl&?z9
if(breakWhile) 58%#DX34M
break; Q-MQ9'
X>NhZ5\
1WY/6[
//count++; OR}c)|1
//if(count>4) 8<.C3m 6h
// siteStop(); F;gx%[$GX
} JNkwEZhHyg
vhsk0$f
qw@puw@D
System.err.println("文件下载结束！"); .pfP7weQ
} C0S^h<iSe*
catch(Exception e){e.printStackTrace ();} w"OP8KA:^T
} L3G \
X@k`3X
D[_|*9BC
//获得文件长度 -8r
public long getFileSize() ~><^'j[
{ T:/,2.l
int nFileLength = -1; 3 n'V\Hvz
try{ L]d-hs
URL url = new URL(siteInfoBean.getSSiteURL()); ]Ar\c["
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D8>enum
httpConnection.setRequestProperty("User-Agent","NetFox"); EI_
@y82L8G/
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int responseCode=httpConnection.getResponseCode(); 1Ab>4UhD
if(responseCode>=400) C8vOE`U,J
{ 4'-|UPhx
processErrorCode(responseCode); OE4+GI.r-
return -2; //-2 represent access is error ]8icBneA~'
} |N}P(GF
:JfE QIN
DXa=|T
String sHeader; 0 ;b[QRmy
b&=5m
6KVnnK
for(int i=1;;i++) /ODXV`3QYI
{ mp9{m`Jb*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +)j1.X
//Utility.log(in.readLine()); h$.:Uj8/
sHeader=httpConnection.getHeaderFieldKey(i); 9lGOWRxR)
if(sHeader!=null) jM$`(Y
{ 3GuH857ov
if(sHeader.equals("Content-Length")) &}?$i7x5
{ ;5tazBy&:C
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); zo[[>MA
break; ^|/](
} W?eu!wL#p
} ~=KJzOS,S
else 0pJ ":Q/2)
break; MXzVgy
} "y_#7K
} [5uRS}!
catch(IOException e){e.printStackTrace ();} A |3tI
catch(Exception e){e.printStackTrace ();} G7)Fk%>
p=C%Hmd5E
m;D- u>o
Utility.log(nFileLength); wKi^C8Z2
u1z
mwY IJy[
return nFileLength; J?Dq>%+^
} K]j0_~3s
,RgB$TcE
:^Fh!br==
//保存下载信息（文件指针位置） )ZBY* lk9
private void write_nPos() YKE46q;J
{ nK$X[KrV'
try{ B*~5)}1op
output = new DataOutputStream(new FileOutputStream(tmpFile)); *;m5'}jsy
output.writeInt(nStartPos.length); :.?gHF.?
for(int i=0;i<nStartPos.length;i++) om |"S
{ 4<cz--g
// output.writeLong(nPos); ?gPKcjgoH!
output.writeLong(fileSplitterFetch.nStartPos); Q}!mx7b0]
output.writeLong(fileSplitterFetch.nEndPos); $uap8nN
} 5*E#*H
output.close(); \MK*by
} c\ia6[3sX
catch(IOException e){e.printStackTrace ();} B9T!j]'
catch(Exception e){e.printStackTrace ();} Rb%%?*|
} cuK,X!O
RPIyO
,SQZD,3v4
//读取保存的下载信息（文件指针位置） YKbaf(K)9
private void read_nPos() P%#*-zCCx
{ 'Fs)Rx}\0
try{ KAsS[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *1 G>YH
int nCount = input.readInt(); GEEW?8
nStartPos = new long[nCount]; uA$<\fnz
nEndPos = new long[nCount]; m85WA # `
for(int i=0;i<nStartPos.length;i++) ?x+Z)`w_
{ =)E,8L
nStartPos = input.readLong(); 6m VuyI
nEndPos = input.readLong(); xGU(n_Y
} Qc[3Fq,f
input.close(); 8E8N6
} !q-f9E4`
catch(IOException e){e.printStackTrace ();} E;d7ch
catch(Exception e){e.printStackTrace ();} @q"m5
} 25NTIzI@@
-F=v6N{
@xeAc0.^
private void processErrorCode(int nErrorCode) iA0q_( \X
{ mo1oyQg8
System.err.println("Error Code : " + nErrorCode); nOQa_G]Gz
} zNY)'
7T"XPV|W6
rU;RGz6}
//停止文件下载 r1<F
public void siteStop() avy"r$v_&
{ Ja SI^go
bStop = true; dJv!Dts')C
for(int i=0;i<nStartPos.length;i++) 'S2bp4G
fileSplitterFetch.splitterStop(); K"uNxZ
->h6j
A].>.AI
} })w*m
} 7HVZZ!>~
//负责部分文件的抓取 kGL1!=>
**FileSplitterFetch.java a6:x"Tv
*/ 7@6g<"I
package NetFox; 'kYwz;gp
.i^7|o:
(mtoA#X1:h
import java.io.*; s;1]tD
import java.net.*; S,U Pl}KF
/B5-Fx7j3
t6BHGX{o
public class FileSplitterFetch extends Thread { \`, [)`
bsd99-_(4
-!0_:m3
String sURL; //File URL yQ3OL#
long nStartPos; //File Snippet Start Position &QG6!`fK}3
long nEndPos; //File Snippet End Position VdP`a(Yd;
int nThreadID; //Thread's ID i/b'4o=8
boolean bDownOver = false; //Downing is over XX1Il;1G#
boolean bStop = false; //Stop identical Iyd?|f"
FileAccessI fileAccessI = null; //File Access interface |oub!fG4
d*oUfiW
DI`%zLDcY
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,-+"^>
{ a=XW[TY1
this.sURL = sURL; hk/! 'd
this.nStartPos = nStart; 1xU3#b&2tC
this.nEndPos = nEnd; 6{,HiY
nThreadID = id; SlSM+F
fileAccessI = new FileAccessI(sName,nStartPos);//定位 k|BHnj
} vA)O{W\o
k8,?hX:
s/:Fwr4q#a
public void run() *cTO7$\[
{ 84i_k
while(nStartPos < nEndPos && !bStop) 3+J0!FVla
{ v|ox!0:#
w'X]M#Q><
oo=#XZkk
try{ *_ +7ni
URL url = new URL(sURL); Gn)y> AN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =&!HwOnp
httpConnection.setRequestProperty("User-Agent","NetFox"); tA$)cg+.
String sProperty = "bytes="+nStartPos+"-"; ~^^ NHq
httpConnection.setRequestProperty("RANGE",sProperty); .)|a2d ~F
Utility.log(sProperty); GpbC M~x
cECi')
jKZt~I
InputStream input = httpConnection.getInputStream(); YF:2>w<
//logResponseHead(httpConnection); h;V,n
w[_x(Ojq;
=SD\Q!fA
byte[] b = new byte[1024]; \<vNVz7.D
int nRead; fbFX4?-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) - O"i3>C
{ yAL1O94
nStartPos += fileAccessI.write(b,0,nRead); ]NhS=3*i+
//if(nThreadID == 1) aS|wpm)K>8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^). )
} D;Gq)]O
OzT#1T1'c
Dml*T(WM>
Utility.log("Thread " + nThreadID + " is over!"); {FN;'Uc
bDownOver = true; iqhOi|!
//nPos = fileAccessI.write (b,0,nRead); G5D2oQa=8
} CK_(b"
catch(Exception e){e.printStackTrace ();} *n(> ^
} pium$4l2#
} xt4)Ya
fag^7rz
7n)&FXK`
//打印回应的头信息 uhV0J97
public void logResponseHead(HttpURLConnection con) XYx6V
{ wFlvi=n/
for(int i=1;;i++) NZu)j["
{ j<pw\k{i
String header=con.getHeaderFieldKey(i); _,6f#t
if(header!=null) ,}xbAA#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); I8H%=Kb?9
Utility.log(header+" : "+con.getHeaderField(header)); IMQ]1uq0$
else dSIH9D
break; U,1AfzlF
} HNa]H;-+5
} NYABmI/0c
Ip}Vb6}
9umGIQHnil
public void splitterStop() rOD1_X-
{ _SZ5P>GIU
bStop = true; gQ~5M'#
} g8ES8SM
rZbEvS
%Y4e9T".
} ">dq0gD
U},=LsDsW4
I~'*$l
/* ZX b}91rzt
**FileAccess.java -Uo?WXP]B'
*//文件访问(定位，写) o@lWBfB*%e
package NetFox; 1u]P4Gf=
import java.io.*; p4VqV6LwD
LF*Q!
1xnLB>jP#
public class FileAccessI implements Serializable{ d0er^ ~
%up}p/?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;52'}%5
RandomAccessFile oSavedFile; Jf:,y~mV
long nPos; 2aNT#J"_
F5gObIJtuY
Jx-wO/
public FileAccessI() throws IOException WVkR56
{ iO!6}yJ*V
this("",0); ++[5q+b
} (L6Cy%KgV
y[0`hSQ)~
j<tq1?? [b
public FileAccessI(String sName,long nPos) throws IOException N~=A
{ [A~G-
oSavedFile = new RandomAccessFile(sName,"rw"); icUT<@0
this.nPos = nPos; *QE<zt
oSavedFile.seek(nPos); Z&!!]"I
} j?(!^ _!m
0?bA$y
9w;?-
public synchronized int write(byte[] b,int nStart,int nLen) 5b#QYu
{ us)*2`?6t
int n = -1; H5wb_yBQ+
try{ J/D|4fC
oSavedFile.write(b,nStart,nLen); ),@f6](
n = nLen; wpPn}[a
} `T!#@&+
catch(IOException e) sLcY,AH
{ Y'"N"$n'_
e.printStackTrace (); +1{fzb>9_
} ;Fl<v@9
cep$_Ja
~waNPjPRG
return n; M<8ML!N0;t
} )JgC$ <
|qjZ38;6
#I\Y=XCY
} RU!?-#*
PE@+w#i7*
7h<> k*E)
/* 32XS`Z
**SiteInfoBean.java ^nDal':*
*/ 6`nR5fh
package NetFox; #ch
}HZ{(?
5vZ#b\;#V
public class SiteInfoBean { EO"C8z'al
p6 xPheD
v"1Po_`
private String sSiteURL; //Site's URL =fG:A(v%}
private String sFilePath; //Saved File's Path g@nk.aRw
private String sFileName; //Saved File's Name 3(lVmfk
private int nSplitter; //Count of Splited Downloading File IS_Su;w>4
Q .RO
"G?9b
public SiteInfoBean() oh}^?p
{//nSplitter的缺省值为5 -@bp4Z=
//default value of nSplitter is 5 a5wDm
this("","","",5); M'jXve(=yF
} Q</h-skLZ
E8[XG2ye
+g\;bLT
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) o'UHStk
{ ubGs/Vzye
sSiteURL= sURL; cx(2jk}6
sFilePath = sPath; LM,fwAX
sFileName = sName; !*a[jhx
this.nSplitter = nSpiltter; [e4![G&y`
6$e]i|e
(r F?If
} d/j@_3'
5:gj&jt;)7
QUP|FIpZ
public String getSSiteURL() _PB@kH#
{ obGWxI%a
return sSiteURL; wGXwzU
} wJIB$3OT
Ph)|j&]
6v47 QW|'
public void setSSiteURL(String value) Di.;<v#FL
{ o~~9!\
sSiteURL = value; \graMu}-
} 5H.Db
%x2b0L\g
)/%S=c
public String getSFilePath() 84`rbL!M
{ W^R'@
return sFilePath; ba&o;BLUy
} BlaJl[Piv
B7 c[4
.Ty,_3+{#p
public void setSFilePath(String value) Vipp /WV
{ ~%P3Pp
sFilePath = value; e[4V%h
} Yo'K pdn
(T;9us0
1ih*gJPpj
public String getSFileName() R+Lk~X^*l'
{ >l2w::l%
return sFileName; 5P\N"Yjx'
} _;G=G5r
iwo$\
~07RFR
public void setSFileName(String value) NhDA7z`b'J
{ 4K,''7N3
sFileName = value; #WEq-0L
} *gSO&O=
.eTk=i[N-
okDJ(AIV+
public int getNSplitter() wP`sXPSmIu
{ coAW9=o}
return nSplitter; eBvW#Hzp
} kH2oK:lN
m<FK;
[d:@1yc
public void setNSplitter(int nCount) 4WG=m}X
{ #Q+R%p[D
nSplitter = nCount; 0x#E4v(UA
} 5mIXyg 0:
} sY^lQN
Bm<^rhJ9
9l l|JeNi
/* J0qXtr%h\
**Utility.java V/&o]b
*/ /s8/q2:
package NetFox; MCd F!{
i* gKtjx
"aA_(Ydzj
public class Utility { Xq%*#)M;
O\JD,w
{9;eH'e
public Utility() >]?Jrs
{ U#"WrWj
TU-c9"7M~
MA"#rOcP
} nrbazyKm
2:~cJk{
//线程睡眠 /=ACdJ
public static void sleep(int nSecond) Wxk;g
{ *#GDi'0
try{ ?&\h;11T
Thread.sleep(nSecond); U%,;N\:_
} Q>[Ce3
catch(Exception e) DUo0w f#D^
{ N*':U^/t4J
e.printStackTrace (); wO!% q[
} >F|qb*Tm7
} d/4ubf+$k
)^(P@D.L
//日志 6d};|#}
public static void log(String sMsg) k%!VP=c4s
{ :@;6
System.err.println(sMsg); IO6MK&R
} #AvEH=:
%A=|'6)k2
QSv^l-<
public static void log(int sMsg) lT3|D?sF
{ 5Abz5-^KH
System.err.println(sMsg); l\Cu1r-z
} c+wuC,
} WN1Jm:5YV
>F~ITk5`Oo
kMqD iJ
/* H8sK}1.
**TestMethod.java ,b4~!V
*/ MyqiBGTb
package NetFox; XUf7yD
S_j1=6#^
IY03"
public class TestMethod { >mew"0Q
KZZOi:
bu_/R~&3{
public TestMethod() YV4 :8At1
{ ///xx/weblogic60b2_win.exe MN\i-vAL8
try{ PRZ8X{h
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); B3eNFS
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *b:u*`@
SiteFileFetch fileFetch = new SiteFileFetch(bean); e$H|MdYIA
fileFetch.start(); q _19&;&
} Yu1QcFuy
catch(Exception e){e.printStackTrace ();} cNx \&vpd
i<J^:7
gh'kUZG a
} xSdN5RN
K_Z+]]$#
Z~:/#?/
public static void main(String[] args) p8$\uo9YQ
{ :|zp8|
new TestMethod(); ~K_]N/ >
} {[my"n2
} CH55K[{<
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