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)); O&@CT])8
} HDj260a
for(int i=0;i<nEndPos.length-1;i++) a-NicjV#
{ V=H:`n3k
nEndPos = nStartPos[i+1]; Bm+Ca:p%
} ,Y7QmbX^
nEndPos[nEndPos.length-1] = nFileLength; 5jsZJpk$
} Fzy5k?R
} q!YAA\'31
Fm[3Btn
wT+\:y
//启动子线程 MAL;XcRR
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `ix&j8E22w
for(int i=0;i<nStartPos.length;i++) n]jw!;
{ z2 mjm
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `r&]Ydu:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), vywpX^KPv
nStartPos,nEndPos,i); 1/J6<FVq
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @jKB[S;JSn
fileSplitterFetch.start(); &W*^&0AV
} nNh5f]]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @el
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); pz]!T'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", EvF[h:C2
nEndPos = " + nFileLength); v4,Dt
// fileSplitterFetch[nPos.length-1].start(); *$@u`nM
No*[@D]g
H`rd bE
//等待子线程结束 (btmg<WT"
//int count = 0; H4<Q}([w
//是否结束while循环 V+t's*9o3
boolean breakWhile = false; l\ VrD2j8
$t0JfDd6Ky
_7'5IA
while(!bStop) upGLZ#
{ _IWLC{%V
write_nPos(); xcH&B%;f
Utility.sleep(500); 9A *gW j
breakWhile = true; ]D,\(|
-L!lJ
x kdC-S
for(int i=0;i<nStartPos.length;i++) d-TpY*v
{ o_03Io ~Bf
if(!fileSplitterFetch.bDownOver) \susLD
{ wYQEm
breakWhile = false; R$;TX^r'o&
break; )T^xDx
} i:1 @ vo
} ?@;#|^k9
if(breakWhile) PJ^qE|X
break; J|`.d46
w8a49Fv
\J;_%-Z
//count++; ;RYIc0%
//if(count>4) DKF '*
// siteStop(); 5<YL^m{/L
} tTWEhHQ`
'UM *7
d{Owz&PL
System.err.println("文件下载结束！"); -F MonM
} .h(iyCxP
catch(Exception e){e.printStackTrace ();} <LN7+7}
} %*#+(A"V
`@#rAW D
b7B|$T,
//获得文件长度 nlA:C>=
public long getFileSize() (p<pF].
{ Y(R.<LtY
int nFileLength = -1; $=) Pky-~
try{ {(I":rt#
URL url = new URL(siteInfoBean.getSSiteURL()); (%mV,2|:20
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z58{YCY
httpConnection.setRequestProperty("User-Agent","NetFox"); PbsxjP
n]i#&[*A(
I5 qrHBJ >
int responseCode=httpConnection.getResponseCode(); l]OzE-*$b
if(responseCode>=400) c=X+uO-
{ mhB2l/
processErrorCode(responseCode); ij;P5OA
return -2; //-2 represent access is error 8|zOgn{
} c3r`T{Kf
2f620
bF5"ab0
String sHeader; <_#2+7Qs
f+8 QAvh
'gHg&E9E&
for(int i=1;;i++) Xj~%kPe
{ ~S\> F\v6'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~H1<8py\J
//Utility.log(in.readLine()); _W^;a
sHeader=httpConnection.getHeaderFieldKey(i); X0REC%
if(sHeader!=null) e5 }amrz
{ {`,)<R>}
if(sHeader.equals("Content-Length")) dqs~K7O^E
{ eze%RjO}
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2=/-,kOL_
break; zTc*1(^
} T5z]=Pd"^
} Q<gUu^rq
else `.J17mQe"
break; >H ?k0M`L
} >##Z}auY
} 1GK>&;
catch(IOException e){e.printStackTrace ();} 3&nN;4~Zx6
catch(Exception e){e.printStackTrace ();} niKfat?
0[e!/*_V
6?;z\AP&
Utility.log(nFileLength); Ih>s2nL
)Yv=:+f
|0Xf":
return nFileLength; FSn3p}FVa
} 6)7cw8^
B(ktIy
imeE&
//保存下载信息（文件指针位置） 4QTHBT+2`
private void write_nPos() 0^sY>N"
{ f 9Kt>2IN
try{ %S'+x[4W
output = new DataOutputStream(new FileOutputStream(tmpFile)); Fj]06~u
output.writeInt(nStartPos.length); U7?v4O]D[
for(int i=0;i<nStartPos.length;i++) 0Qq<h;8xEc
{ =*"8N-FU
// output.writeLong(nPos); >0W P:-\*
output.writeLong(fileSplitterFetch.nStartPos); %qiVbm0
output.writeLong(fileSplitterFetch.nEndPos); +vaA P=
} Ikw@B)0}
output.close(); t%%()!|)j
} Q;g7<w17
catch(IOException e){e.printStackTrace ();} IWq#W(yM
catch(Exception e){e.printStackTrace ();} X-(4/T+v
} JO+tY[q
&T~X`{V]`
DA.k8M
//读取保存的下载信息（文件指针位置） W\NC3]
private void read_nPos() =$fz</S=J
{ KmTFJ,iM
try{ w"wW0uE^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); qz{9ND|)
int nCount = input.readInt(); M/dgW`c
nStartPos = new long[nCount]; >36,lNt
nEndPos = new long[nCount]; X;N?L%Pp
for(int i=0;i<nStartPos.length;i++) 6-fv<Pn
{ R$8{f:Pj
nStartPos = input.readLong(); yDwh]t
nEndPos = input.readLong(); 3h d30o
} 6#!CBY^{
input.close(); -(]CFnD_N
} f!`?_
catch(IOException e){e.printStackTrace ();} ^9:`D@Z+
catch(Exception e){e.printStackTrace ();} V5z2.} 'o-
} eqsmv[
j~G(7t
}#7rg_O]>
private void processErrorCode(int nErrorCode) O~6%Iz`
{ .Zv~a&GE
System.err.println("Error Code : " + nErrorCode); uVCH<6Cp
} Z|%h-~
o3/o2[s
#-<Go'yF
//停止文件下载 4&sf{tI
public void siteStop() hHU=lnO
{ ^2nrA pF
bStop = true; 9`*Eeb>
for(int i=0;i<nStartPos.length;i++) H8FvI"J
fileSplitterFetch.splitterStop(); $_E.D>5^%7
k#Sr;"
/HpM17
} +tT"
} ~x\uZ^:
//负责部分文件的抓取 >&KH!:OX|
**FileSplitterFetch.java Q(nTL WW
*/ q.`<q
package NetFox; G rp{ .
>kK@tJn
ZBK0`7#&EH
import java.io.*; |HD>m'e
import java.net.*; i7XY3yhC
{pIh/0
$t.oGd@N
public class FileSplitterFetch extends Thread { LhbdvJAk@
jez0 A
H.ksI;,
String sURL; //File URL ,3Q~X$f
long nStartPos; //File Snippet Start Position w;`Jj-
long nEndPos; //File Snippet End Position 6dR+qJa6i
int nThreadID; //Thread's ID >5Yn`Fc5
boolean bDownOver = false; //Downing is over k`8O/J
boolean bStop = false; //Stop identical t4_yp_
FileAccessI fileAccessI = null; //File Access interface ?J2A1iuq3
<&l$xn
MmN{f~Kq9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException XNWtX-[^@
{ gZ$ 8Y7
this.sURL = sURL; ~3?-l/$
this.nStartPos = nStart; 5 ix*wu`,
this.nEndPos = nEnd; !q\=e@j-i
nThreadID = id; f?Zjd&|Ch
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p{^:b6
} .iRKuBM/
+ig%_QED[\
$qQYxx@
public void run() ]O"f%
{ dDpAS#'s\
while(nStartPos < nEndPos && !bStop) (4cdkL
{ .Rk8qRB
.cHgYHa
k i<X^^
try{ l5{60$g
URL url = new URL(sURL); UrizZ5a
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w5HIR/kP
httpConnection.setRequestProperty("User-Agent","NetFox"); m7'<k1#"Y
String sProperty = "bytes="+nStartPos+"-"; UJI2L-;Ul
httpConnection.setRequestProperty("RANGE",sProperty); FfJ;r'eGs
Utility.log(sProperty); MF4(
B@&sG 5ES
W/!P1M n
InputStream input = httpConnection.getInputStream(); djOjd,
//logResponseHead(httpConnection); 5;/n`Bd
CW &z?Bra
uGMzU&+
byte[] b = new byte[1024]; +M0pmK!
int nRead; '6dVe2V
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Snf_{A<
{ gM3:J:N
nStartPos += fileAccessI.write(b,0,nRead); e.n(NW
//if(nThreadID == 1) "=Br&FN{|
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e c&Y2
} kL*P 3 0
+twoUn{#
?7aZU
Utility.log("Thread " + nThreadID + " is over!"); U"k$qZ[
bDownOver = true; -+rzc&h
//nPos = fileAccessI.write (b,0,nRead); E{|B&6$[}
} H`CID*Ji
catch(Exception e){e.printStackTrace ();} V%oZT>T3
} (SBhU:^h
} 90<g=B
{-\U)&6#v
MNd\)nX
//打印回应的头信息 ."$t&[;s
public void logResponseHead(HttpURLConnection con) ~(^P(
{ 2IJK0w@
for(int i=1;;i++) H{*Dc_
{ :25LQf^nz
String header=con.getHeaderFieldKey(i); +lx&$mr?
if(header!=null) 2|je{
//responseHeaders.put(header,httpConnection.getHeaderField(header)); A`Z/B[)
Utility.log(header+" : "+con.getHeaderField(header)); M/?,Qii
else uAn}qrqE9
break; 5daq}hsQs
} ]c/E7|0Q
} 2FIL@f|\7z
y/Xs+ {x
'k,2*.A
public void splitterStop() la3B`p
{ )\akIA
bStop = true; R@o&c%K"
} 'o-4'
,QcS[9$
.G O0xnm
} tqGrhOt
JXB)'d0
w>%@Ug["
/* wh8';LZ>R
**FileAccess.java Y %"Ji[
*//文件访问(定位，写) j7~FR{:j
package NetFox; h:?^0b!@
import java.io.*; U] LDi8
5'} V`?S
xLW$>;kI
public class FileAccessI implements Serializable{ ``-N2U5
L'= \|r
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 vF27+/2+R
RandomAccessFile oSavedFile; XnyN*}8
long nPos; QKG3>lU
3Qy@^"
q)k:pQ
public FileAccessI() throws IOException 3z8i0
{ ue_wuZi
this("",0); '$9o(m#
} YWFE*wQ!
^jL '*&l
R BYhU55B
public FileAccessI(String sName,long nPos) throws IOException |6E_N5~
{ o`bc/3!
oSavedFile = new RandomAccessFile(sName,"rw"); 2d&F<J<sU
this.nPos = nPos; ;k<dp7^
oSavedFile.seek(nPos); 80=0S^gEZ
} j6m;03<|
K zWo}tT
&`r/+B_W
public synchronized int write(byte[] b,int nStart,int nLen) uz8LF47@:-
{ n#(pT3&
int n = -1; k#].nQG
try{ [l23b{
oSavedFile.write(b,nStart,nLen); q(KjhM
n = nLen; g>lZs
} ]S6Gz/4aV+
catch(IOException e) [X(4( 1i
{ aFnel8
e.printStackTrace (); pXk^EV0
} or]v]*:~l
7UfNz60+~
ZVjB$-do
return n; WXQ@kQD
} X6HaC+P
02-ql F@i
MEDh
} /F0q8j0
^""edCs
I|@+O#
/* /DQYlNa
**SiteInfoBean.java gEh/m.L7
*/ da$FY7
package NetFox; zxyl+tU &
Tgdy;?
-k'<6op
public class SiteInfoBean { G@8)3 @
H[=\_X1o(
(80m'.X
private String sSiteURL; //Site's URL s0SzO,Vi
private String sFilePath; //Saved File's Path 4#$#x=:
private String sFileName; //Saved File's Name ? #K|l*
private int nSplitter; //Count of Splited Downloading File ATs_d_Sz
K`4lL5oH
{r^_g(.q
public SiteInfoBean() :Jd7q.
{//nSplitter的缺省值为5 4V+bE$Wu
//default value of nSplitter is 5 1h,iWHC
this("","","",5); /5@YZ?|#2
} &.)=>2
|2(q9j
;ArwEzo(
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) CFtQPTw
{ }%wd1`l7
sSiteURL= sURL; 3lP;=*m.
sFilePath = sPath; 'a~@q~!
sFileName = sName; ~ ld.I4
this.nSplitter = nSpiltter; t>j_C{X1(
f}:C~L!
a'J0}j!
} +-izC%G
LF dvz0
L:i&OCU2k
public String getSSiteURL() >*-%:ub
{ GP};~
return sSiteURL; #AD_EN9
} VvhfD2*T
d ^bSV4
ho\1[xS
public void setSSiteURL(String value) fM=o?w6v
{ \6b~$\~B
sSiteURL = value; u$nzpw0=H
} 6!<I'M'[e
"Y&I#&$b\
[&lK.?V)
public String getSFilePath() il0K^i
{ O. * 0;5
return sFilePath; (v]%kXy/G
} 3?93Pj3oPt
3[m~-8
@r"\bBi
public void setSFilePath(String value) mqSVd^
{ }lZEdF9GhG
sFilePath = value; GBJLB
} cO?*(e1m=
74%vNKzc~
~1G^IZ6
public String getSFileName() ptCF))Zm'
{ \:vF FK4a
return sFileName; WogUILB
} c{q+h V=
}Fe~XO`
BQu |qrq
public void setSFileName(String value) o[C^z7WG0
{ r%,?uim#
sFileName = value; N,~O+
} {cK<iQJ
u0C:q`;z
EC+t-:a]
public int getNSplitter() CK_dEh2c
{ j7I=2xnTWu
return nSplitter; E7uIur=g!
} V?mP7
bWFa{W5!
?ANWI8'_j
public void setNSplitter(int nCount) ~f<']zXv
{ ~k*]Z8Z
nSplitter = nCount; [ 8Ohg
} $>rt0LOF
} mGT('iTM4
U:7h>Z0W
+){^HC\7h
/* l+ }=D@l
**Utility.java f:;-ZkIU ?
*/ *D]:{#C*
package NetFox; DV5hTw0
Q'<AV1<
.S` q2C\
public class Utility { :V/".K-:J
6H#:rM
wE .H:q4&
public Utility() Ev fvU:z
{ x ;DoQx
*>m[ZJd%=
~Ztn(1N
} +k`L8@a3&
KzHN|8$o
//线程睡眠 [LVXXjkFI
public static void sleep(int nSecond) |$WHw*F^
{ 9*"
try{ -]3K#M)s
Thread.sleep(nSecond); TmgC {_
} r)<A YX]J
catch(Exception e) OUv)`K
{ P\"kr?jZP
e.printStackTrace (); T?3Q<[SmI
} J=A)]YE
} [S6u:;7
fUw:jExz
//日志 "Q:Gd6?h;
public static void log(String sMsg) x^s,<G
{ Q 3WD!Z8y
System.err.println(sMsg); cU;Bm}U
} w2B)$u
wNa5qp 0
=!TUf/O-
public static void log(int sMsg) L>Y+}]~
{ C[FHqo9M?H
System.err.println(sMsg); Ym'h vK
} 8h] TI_
} f&-`+V}U
v :pT(0N
1}VaBsEV
/* yP"2.9\erH
**TestMethod.java 5/.W-Q\pl}
*/ yi$CkG}
package NetFox; &xGdKH
{B$CqsvJ
80nEQT y
public class TestMethod { 7L~*%j
:WB uU
'#Wx@
public TestMethod() V]zZb-m=
{ ///xx/weblogic60b2_win.exe XYU5.
try{ V.B@@ ;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,_V V;P
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); BJ UG<k
SiteFileFetch fileFetch = new SiteFileFetch(bean); y##h(y
fileFetch.start(); .}__XWK5
} CW1l;uwtU
catch(Exception e){e.printStackTrace ();} 9p_?t'&>q
@a8lF$<
Tm"H9
} oidZWy
Jm_)}dj3o
'_v~+
public static void main(String[] args) V%-hP~nyBx
{ V60L\?a
new TestMethod(); Q[OwP
} {!Qu(%
} ^4sfVpD2!
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