http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); 1$W!<:uh
} ~}116K
for(int i=0;i<nEndPos.length-1;i++) KP(Bu0S
{ N@>S>U8C
nEndPos = nStartPos[i+1]; EIfrZg7R
} o_5@R+&
nEndPos[nEndPos.length-1] = nFileLength; PTh Ya
} s5dh]vNN
} Lsz`nD5
WveFB%@`;
1,J.
//启动子线程 x@ O:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; wtKh8^:YD
for(int i=0;i<nStartPos.length;i++) (qrT0D6
{ YGO@X(ej,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5W48z%MN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), fYi!Z/Ck2
nStartPos,nEndPos,i); 6M9rC[h\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H6eGLg={
fileSplitterFetch.start(); #Grm-W9E
} L5W>in5(
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $9~1s/('
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @:@rks&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", vX\e* v
nEndPos = " + nFileLength); GSH{1VS_b
// fileSplitterFetch[nPos.length-1].start(); wMoAvA_oS
@!da1jN
+*q@=P,
//等待子线程结束 /~[R u
//int count = 0; >>r:L3<!
//是否结束while循环 jo*9QO
boolean breakWhile = false; -G 'lyH
YovY0nO
v=>Gvl3&U
while(!bStop) $\ '\@3o
{ G;;~xfE'
write_nPos(); 96avgyc
Utility.sleep(500); luT8>9X^:a
breakWhile = true; 86g+c
c"ztrKQQ
'Ap5Aq
for(int i=0;i<nStartPos.length;i++) M)7enp) F.
{ V]}b3Y!(
if(!fileSplitterFetch.bDownOver) 8E+l;2
{ jlBCu(.,_
breakWhile = false; 3@L%#]xwi
break; Cs{f'I
} h~p}08
} hd;I x%tq>
if(breakWhile) rzHa&:Y
break; $5r,Q{;$
O@rb4(
}TW=eu~
//count++; ,GIqRT4K
//if(count>4) MV}]i@V
// siteStop(); `%3p.~>
} ErC[Zh"''
N3<Jh
E6k&r}
System.err.println("文件下载结束！"); YC<I|&"
} P1n@E*~V5
catch(Exception e){e.printStackTrace ();} MavO`m&Cg
} }q W aE
G65N:
@`D6F;R
//获得文件长度 8A.7=C' z
public long getFileSize() 'wrpW#
{ tqCg<NH.!m
int nFileLength = -1; [@Y q^.6t
try{ C6~dN&q
URL url = new URL(siteInfoBean.getSSiteURL()); /p0LtUMu
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); us%RQ8=k
httpConnection.setRequestProperty("User-Agent","NetFox"); zQ}N mlk
CaBS0' n
RzQS@^u*F0
int responseCode=httpConnection.getResponseCode(); ~*[4DQ[\
if(responseCode>=400) iGLYM-
{ 5i#w:O\cz
processErrorCode(responseCode); VYo;[ue([
return -2; //-2 represent access is error =osw3"ng
} ZiYzsn
W2h[NimU
0K0=Ob^(e
String sHeader; :OaQq@V
[)>8z8'f
[_b='/8
for(int i=1;;i++) D(U3zXdO
{ \|`Pul$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }tO<_f))
//Utility.log(in.readLine()); g8A{aHb1}
sHeader=httpConnection.getHeaderFieldKey(i); 9mphj)`d;#
if(sHeader!=null) ^!_7L4&y
{ eh4"_t
if(sHeader.equals("Content-Length")) _4B iF?1
{ |o=ST
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5XO'OSdYq
break; @]wem
} M;V#Gm
} FKnQwX.0
else .0W4Dp
break; C+m^Z[
} h=r< B\Pa
} JO{- P
catch(IOException e){e.printStackTrace ();} wf<`J/7u
catch(Exception e){e.printStackTrace ();} yPG\ &Bo
)60f
>@"3Q`
Utility.log(nFileLength); IYg3ve`x
Y_>-p(IH
~V"cLTj"
return nFileLength; C|IQM4
} 4$DliP
=k<4mlok^
<;0N@
//保存下载信息（文件指针位置） ';|>`<
private void write_nPos() {^5<{j3e
{ \If!5N
try{ zn;Hs]G
output = new DataOutputStream(new FileOutputStream(tmpFile)); $o$Ev@mi
output.writeInt(nStartPos.length); jsi#l
for(int i=0;i<nStartPos.length;i++) c$<O0dI
{ #0<y0uJ(y
// output.writeLong(nPos); Sb9=$0%\
output.writeLong(fileSplitterFetch.nStartPos); f(s3TLM
output.writeLong(fileSplitterFetch.nEndPos); K-k.=6mS
} t,1!`/\
output.close(); 5QFXj)hR+4
} E(3+o\w
catch(IOException e){e.printStackTrace ();} &G|jzXE
catch(Exception e){e.printStackTrace ();} 6O@ ^`T
} m#'rI=}!
Q1I_=fT
*5_8\7d
//读取保存的下载信息（文件指针位置） y_4krY|Zx
private void read_nPos() #JR,C -w
{ &c?hJ8"
try{ Ed0>R<jR9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); q|$>H6H4b
int nCount = input.readInt(); W*rU,F|9
nStartPos = new long[nCount]; ,{ L;B
nEndPos = new long[nCount]; f'`nx;@X
for(int i=0;i<nStartPos.length;i++) Re,$<9V
{ s!;VUr\
nStartPos = input.readLong(); pg}+lYGP
nEndPos = input.readLong(); .UhBvHH
} ZDkD%SCy
input.close(); ,dj*p,J
} CVSsB:H6e
catch(IOException e){e.printStackTrace ();} s@)"IdSA(
catch(Exception e){e.printStackTrace ();} EfBVu
} Ril21o! j
&Wz`>qYL*
BUA6(
private void processErrorCode(int nErrorCode) n:^"[Le
{ 5ih"Nds[H
System.err.println("Error Code : " + nErrorCode); HMS9y%zl/
} :OQ:@Yk
$,QpSK`9i
E4v_2Q -w
//停止文件下载 #u<oEDQ
public void siteStop() 51ajE2+X&
{ ,F`KQ )\"
bStop = true; sAD P~xvU
for(int i=0;i<nStartPos.length;i++) K)Xs L
fileSplitterFetch.splitterStop(); W]yClx \
+G!jKta7B
;4/dk_~p]
} D"x$^6`c}
} F@K*T2uh
//负责部分文件的抓取 q~Q)'*m
**FileSplitterFetch.java ,JQxs7@2k
*/ 0n<(*bfW
package NetFox; w^dueP7J
$uFh$f
Q{l*62Bx
import java.io.*; v<7Gln
import java.net.*; D _bkUR1
+{C9uY)$vf
`J=1&ae{
public class FileSplitterFetch extends Thread { >\?z37:T
Yf!*OGF
eb.cq"C
String sURL; //File URL @( n^S?(
long nStartPos; //File Snippet Start Position 16[-3cJ T
long nEndPos; //File Snippet End Position `Ge+(1x
int nThreadID; //Thread's ID jqX@&}3@
boolean bDownOver = false; //Downing is over >Z2,^5P{
boolean bStop = false; //Stop identical /\-2l+y>J
FileAccessI fileAccessI = null; //File Access interface =,C9O
x'M^4{4[
y3KcM#[
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ra9cD"/J &
{ =##s;zj(%
this.sURL = sURL; i (%tHa37
this.nStartPos = nStart; gaw4NZd)0
this.nEndPos = nEnd; hLyTUt~\L
nThreadID = id; r{q}f)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Q9yGQu
} =~\]3g
Xb<DpBrk
I NPYJ#%
public void run() ^)hAVf~E
{ @m/;ZQ
while(nStartPos < nEndPos && !bStop) #j^('K|
{ Wiq{wxe
joChML_
O/DAf|X|
try{ q4Oxs
URL url = new URL(sURL); 7ZV~op2Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yNrinYw
httpConnection.setRequestProperty("User-Agent","NetFox"); T}n}.JwU
String sProperty = "bytes="+nStartPos+"-"; J+}+"h~.
httpConnection.setRequestProperty("RANGE",sProperty); {ywXz|TP
Utility.log(sProperty); wUK7um
o9m
tIGVB+g{F
InputStream input = httpConnection.getInputStream(); B=Zl&1
//logResponseHead(httpConnection); lJ:M^.Em0
d`9W
jF38kj3O7
byte[] b = new byte[1024]; c?!YFm
int nRead; ${eY9-r_%
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) /B,:<&_-
{ RHwaJ;:)#
nStartPos += fileAccessI.write(b,0,nRead); ?o~:'Z
//if(nThreadID == 1) 861i3OXVE>
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pKt-R07*
} x7P([^i
6o=qJ`m[?
Q;$ 9qOF
Utility.log("Thread " + nThreadID + " is over!"); a>wfhmr
bDownOver = true; eeW' [
//nPos = fileAccessI.write (b,0,nRead); 5:Yck<
} >aEL;V=}P
catch(Exception e){e.printStackTrace ();} -A/ds1=;
} w=f0*$ue+w
} H+4=|mkQ
M"=8O>NZ2
[_y9"MMwn
//打印回应的头信息 xn(+G$m
public void logResponseHead(HttpURLConnection con) hq/J6 M
{ ,M\j%3
for(int i=1;;i++) ss?]
{ _Ry_K3K
String header=con.getHeaderFieldKey(i); 33Ssylno
if(header!=null) KxO/]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); x}tKewdOSe
Utility.log(header+" : "+con.getHeaderField(header)); =2^Vgc
else [RAj3Fr0
break; `WH[DQ
} JNh=fvO2i
} SHMl%mw
1#grB(p?
n!GWqle
public void splitterStop() y L*LJ
{ f#@S*^%V$
bStop = true; WK pUn8&N
} LO"_NeuL
RnHQq'J|\
)T>8XCL\}
} 82lr4
{tPnj_|n<
:@.C4oq
/* m&Lt6_vi
**FileAccess.java HtxLMzgz<<
*//文件访问(定位，写) brb[})}
package NetFox; ya:sW5fk
import java.io.*; j5kA^MTG
^w>&?A'!
aiYo8+{!#
public class FileAccessI implements Serializable{ kEO1TS
7'Lp8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 aC`Li^
RandomAccessFile oSavedFile; }/20%fP
long nPos; y =R aJm
NdZ)[f:2
}d_<\
public FileAccessI() throws IOException DB#$~(o
{ `%|u!
this("",0); *xPB<v2N:P
} ugno]5Ni
Qh^R Ax
/mc*Hc8R8
public FileAccessI(String sName,long nPos) throws IOException @8|Gh]\P
{ D-6
oSavedFile = new RandomAccessFile(sName,"rw"); ,s0 9B
this.nPos = nPos; pDGT@qJ
oSavedFile.seek(nPos); Rfht\{N 7
} <KtBv Ip]
5:c;RRn
+kM\ D~D1
public synchronized int write(byte[] b,int nStart,int nLen) {ih:FcI
{ ;d4y{
int n = -1; 6z Ay)~
try{ Jz0K}^Dj[
oSavedFile.write(b,nStart,nLen); "=qv#mZ#9
n = nLen; z=qWJQ
} mmHJh\2v
catch(IOException e) CJp-Y}fGEA
{ ZPlPN;J^1
e.printStackTrace (); Twx{' S
} H<,bq*@
Uj,g]e8e
*6XRjq^#
return n; V{0%xz #
} }t\ 10nQ
?~,JY
gwiR/(1
} Tv\HAK<N
~ 7}]
ilv_D~|
/* 4`s)ue
**SiteInfoBean.java `y2ljIWJ
*/ -bA!PeI
package NetFox; Pg Syt
X'@'/[?
RJx{eck%
public class SiteInfoBean { zka?cOmYF[
^sV|ck
.Vmtx
private String sSiteURL; //Site's URL +8f>^*:u
private String sFilePath; //Saved File's Path 2 5Q+1
private String sFileName; //Saved File's Name +`| mJa
private int nSplitter; //Count of Splited Downloading File <7^Kt7k
3p_b8K_bG
@bT3'K-4
public SiteInfoBean() dQ<(lzS~
{//nSplitter的缺省值为5 g5}lLKT
//default value of nSplitter is 5 ]YsR E>
this("","","",5); B9*Sfw%
} @^!\d#/M
\!<"7=(J{4
b/nOdFO@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Q2"WV
{ gLD{1-v
sSiteURL= sURL; f*<ps o
sFilePath = sPath; B'p5M.6d#:
sFileName = sName; b66R}=P l
this.nSplitter = nSpiltter; [/OQyb4F<
xl8#=qmCD
y\#o2PVmY
} nhewDDu
3u_oRs
b@6:1x
public String getSSiteURL() Fc'[+L--Q
{ \5hw9T&[B
return sSiteURL; fLNag~
} GJ`UO
RM,'o[%
+9zA^0
public void setSSiteURL(String value) ~KRnr0
{ q5p e~
sSiteURL = value; vLDi ;
} )b92yP{
\f"1}f
*S4aF*Qk
public String getSFilePath() TKOP;[1h
{ 1Nj=B_T
return sFilePath; f=m/ -mAA
} o?wt$j-
&$#99\/
.S!-e$EJ
public void setSFilePath(String value) O>AFF@=
{ Pq?*C;D
sFilePath = value; v9rVpYc"
} o1k#."wHr
QKccrAo
FJwt?3\u5
public String getSFileName() 7`fY*O6
{ Dtt-|_EMS
return sFileName; X*O9JGh
} N09KVz2Q
>vVw!.fJ
-:SIS`0s
public void setSFileName(String value) El (/em
{ 8l23%iWxe
sFileName = value; JZ=5Bpw
} {ma;G[!
GV8)Kor%
kA^A mfba
public int getNSplitter() a,n93-m(m
{ jNc<~{/
return nSplitter; GNU;jSh5
} s;1e0n
sPCMckt
|>2:eH
public void setNSplitter(int nCount) CH;;V3
{ _~A~+S}
nSplitter = nCount; DYRE1!
} A1-qtAO]
} ZEGd4_ux
0d4cE10
85z;Zt0{
/* cZi[(K
**Utility.java w>vH8f
*/ KlUqoJ;"
package NetFox; d#\W hRE
"2;N2=~7
x=,8[W#XT
public class Utility { GN%(9N'W
T~J?AKx
]l[2hy= cV
public Utility() l>7r2;
{ J]fS({(\I
|zpx)8Q
?@UAL.y
} GMm'of#
A5XR3$5P
//线程睡眠 r1Z<:}ZwK
public static void sleep(int nSecond) r)b<{u=]
{ (WE,dY+.
try{ }-p,iTm
Thread.sleep(nSecond); zu<3^=3
} @^?XaU
catch(Exception e) YwAnqAg
{ kon=il<@
e.printStackTrace (); Ei~f`{i
} 'qy#)F
} 7lU.Nit
ow.j+<M
//日志 oT3Y!Y3=<
public static void log(String sMsg) #C\4/g?=,
{ Jqru AW<
System.err.println(sMsg); >Z\BfH
} p5<2N
/2@["*^$
4;*f1_;f~
public static void log(int sMsg) %-j&e44
{ 0{R/<N
System.err.println(sMsg); I/B1qw;MN
} xK;e\^v
} "^%Z'ou
(p |DcA]BX
Zq*eX\#C
/* uA\J0"0;}
**TestMethod.java \L[i9m|e
*/ Z;b+>2oL
package NetFox; 1S%}xsR0
"s]y!BLk
>&Fa(o;*
public class TestMethod { NHiq^ojk
rAXX}"l6s
|Td5l?
public TestMethod() 6fwY$K\X
{ ///xx/weblogic60b2_win.exe T=\!2gt
try{ r(`nt-o@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7&6Y
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); HomN/wKh
SiteFileFetch fileFetch = new SiteFileFetch(bean); i&Kz*,pt
fileFetch.start(); $(q8y/,R*-
} ]}LGbv"`A
catch(Exception e){e.printStackTrace ();} xjq0D[
VzwPBQ -
@2' %o<lF
} (ZPXdr
7ZFJexN]
o4)hxs
public static void main(String[] args) TnE+[.Qu
{ /F~X,lm*~
new TestMethod(); +R[4\ hC0Y
} oJY[{-qW
} #@Y/{[s|@
点击下载更多相关资料