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)); x#,nR]C
} "qvJ-Y
for(int i=0;i<nEndPos.length-1;i++) W<s5rMx
{ <c$K3
nEndPos = nStartPos[i+1]; Q=Y1kcTOn
} UfAN)SE"
nEndPos[nEndPos.length-1] = nFileLength; Mg76v<mv<
} ?wYvBFRn7"
} K1*]6x,
h!h<!xaclW
:~{x'`czJ
//启动子线程 :ZP`Y%dt'
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^TCgSi7k`L
for(int i=0;i<nStartPos.length;i++) qJPEq%'Q
{ w.6Gp;O
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %q)*8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), QpC,komLJ
nStartPos,nEndPos,i); |>L|7>J{<d
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); leomm+f^
fileSplitterFetch.start(); ~k[q:$T
} =[T_`*s&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NM:\T1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); l&4+v.zr
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", -P'KpX:]hd
nEndPos = " + nFileLength); i#W0
// fileSplitterFetch[nPos.length-1].start(); 'k(aZ"
XDcA&cM}p
EAi!"NJ
//等待子线程结束 |#_`aT"
//int count = 0; Eggdj+
//是否结束while循环 wEJ) h1=)^
boolean breakWhile = false; s`Z'5J;S
v<c@bDZ>
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while(!bStop) .S=^)
{ qe"t0w|U?
write_nPos(); 7G<v<&
Utility.sleep(500); 3'D<'S}[
breakWhile = true; $^;b 1bnO
FSn&N2[D
3A>Bnb
for(int i=0;i<nStartPos.length;i++) <qpDAz4k
{ ap[{`u
if(!fileSplitterFetch.bDownOver) j9G1 _
{ a2tRmil
breakWhile = false; 38Bh9>c3
break; mFdj+ &2\
} eH9Ofhsry
} /<WK2G
if(breakWhile) b ?-VZA:
break; i1E~F
f R?Xq@c
N 2\lBi
//count++; 8kwe._&)
//if(count>4) ohPCYt
// siteStop(); ]~H\X":[>
} oPPxjag\
|0e7<[
IxQ(g#sj_k
System.err.println("文件下载结束！"); =A< Fcl\Rz
} 1<ic 5kB
catch(Exception e){e.printStackTrace ();} |JD"iP:
} 4$^\s5K
]gHi5]\NC
sS5:5i
//获得文件长度 h &R1"
public long getFileSize() ,|r%tNh<8$
{ D#I^;Xg0h
int nFileLength = -1; u6#=<FD/}
try{ 1!4-M$-
URL url = new URL(siteInfoBean.getSSiteURL()); ?=\&O=_ln
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5i42o+'
httpConnection.setRequestProperty("User-Agent","NetFox"); i G%h-
#-*#? -
0~:Eo89
int responseCode=httpConnection.getResponseCode(); Z:2a_Atm
if(responseCode>=400) HpX ;:/I
{ ;I^+u0ga
processErrorCode(responseCode); g*& |Eq/
return -2; //-2 represent access is error |{a`,%mw
} "7&DuF$s)
9h$08l
jLZ^EM-
String sHeader; c{X:0man
lPywrTG0
" A}S92
for(int i=1;;i++) X5hamkM*m
{ f*ICZM
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Z&VH7gi
//Utility.log(in.readLine()); th?w&;L
sHeader=httpConnection.getHeaderFieldKey(i); {#,eD
if(sHeader!=null) RrG5`2
{ 7i$)iNW
if(sHeader.equals("Content-Length")) sOY+X
{ $yA>j (k4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x&kM /z?/
break; +"i|)yUYy}
} K_" denzT+
} &*4C{N
else nbECEQ:|B
break; dpPu&m+
} ZHWxU
} 5@kNvi
catch(IOException e){e.printStackTrace ();} oXxY$x*R1
catch(Exception e){e.printStackTrace ();} \[57Dmo
,R~{$QUl
|v6kZ0B<
Utility.log(nFileLength); 3m#/1=@o
^z%ShmM&LZ
.a0]1IkatV
return nFileLength; P,}cH;w6Ck
} fUg<+|v*
`v|w&ty*
1ab_^P
//保存下载信息（文件指针位置） ,_N+t:*#0
private void write_nPos() pmIOV~K
{ {|E'
try{ 7^2
output = new DataOutputStream(new FileOutputStream(tmpFile)); O_kBAC-|R(
output.writeInt(nStartPos.length); fy6<KEea
for(int i=0;i<nStartPos.length;i++) NZTG)<
{ UCz\SZ{za
// output.writeLong(nPos); }^@Q9<P^E
output.writeLong(fileSplitterFetch.nStartPos); iaAj|:
output.writeLong(fileSplitterFetch.nEndPos); IOjp'6Yr
} 5x=aJl;G
output.close(); @5rl;C
} VPh0{(O^=
catch(IOException e){e.printStackTrace ();} ;Eer
catch(Exception e){e.printStackTrace ();} V8Fp1?E9S
} {#_CzI.0f
ye-EJDZN
?DwI>< W
//读取保存的下载信息（文件指针位置） 4Ucs9w3[
private void read_nPos() aJ{-m@/5
{ e}u68|\EC
try{ Hrk]6*
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \|gE=5!Am=
int nCount = input.readInt(); z[0+9=<Y
nStartPos = new long[nCount]; <0w"$.K#3
nEndPos = new long[nCount]; cR*5iqA
for(int i=0;i<nStartPos.length;i++) @BfJb[A#
{ :< d.
nStartPos = input.readLong(); I0qSx{K
nEndPos = input.readLong(); 0'QX*xfa>
} J2BCaAwEP,
input.close(); XsXO S8
} <?>1eU%
catch(IOException e){e.printStackTrace ();} nc2=S^Fqu
catch(Exception e){e.printStackTrace ();} RXD*;B$v
} X>la!}sV
UD!-.I]
:Rftn6!
private void processErrorCode(int nErrorCode) e2><Y<
{ GGQ%/i]:
System.err.println("Error Code : " + nErrorCode); %6%~`((4
} Pss$[ %
V`WSZ
3OlXi9>3
//停止文件下载 z]%c6ty
public void siteStop() I,lX;~xb
{ u^4$<fd
bStop = true; ..K@'*u
for(int i=0;i<nStartPos.length;i++) -`8pahI
fileSplitterFetch.splitterStop(); +v.<Fw2k#
]<xzCPB
B@ xjwBUk
} VRs|";
} [pRRBMho
//负责部分文件的抓取 1`Ig A0V`"
**FileSplitterFetch.java iCtDV5
*/ 0R-J \
package NetFox; Ym8 V)
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l"rX'g?
import java.io.*; :u9OD` D
import java.net.*; gr^TL1(
JE*d-
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public class FileSplitterFetch extends Thread { f|'0FI
i<b-$9
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String sURL; //File URL (k^o[HF
long nStartPos; //File Snippet Start Position ,6 IKkyD
long nEndPos; //File Snippet End Position @dyh:2!
int nThreadID; //Thread's ID cFZcBiw
boolean bDownOver = false; //Downing is over *8I"7'xh
boolean bStop = false; //Stop identical )vsX (/WU
FileAccessI fileAccessI = null; //File Access interface <0!O'" "J
jAcrXB*
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException W5Uw=!LdEY
{ =o5|W'>`
this.sURL = sURL; S0' ACt`
this.nStartPos = nStart; S aH':UN
this.nEndPos = nEnd; dJjkH6%}
nThreadID = id; S?[@/35)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _M) G
} X5tx(}j
,(A $WT@e
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public void run() eev-";c
{ B2,c_[UZ.
while(nStartPos < nEndPos && !bStop) )kT.3 Q
{ {ldt/dl~
9vauCIfVC
^m/7TwD
try{ !+u K@z&G
URL url = new URL(sURL); agkGUK/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +^DDWVp
httpConnection.setRequestProperty("User-Agent","NetFox"); QnA~,z/.w
String sProperty = "bytes="+nStartPos+"-"; }n( ?|
httpConnection.setRequestProperty("RANGE",sProperty); .>a [
Utility.log(sProperty); {SkE`u4Sz
= inp>L
o/6VOX
InputStream input = httpConnection.getInputStream(); #\8"d
//logResponseHead(httpConnection); k2O3{xIjc
#,9s\T
2e9.U/9
byte[] b = new byte[1024]; ifcp!l+8
int nRead; GO)5R,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $Jo4n>/
{ ph$vP;}
nStartPos += fileAccessI.write(b,0,nRead); &/n*>%2
//if(nThreadID == 1) 1Ror1%Q"?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3yrb7Rn3
} neQ~h4U"
bd\%K`JQ{
s1]m^,
Utility.log("Thread " + nThreadID + " is over!"); yv|`A2@9
bDownOver = true; f_2(`T#
//nPos = fileAccessI.write (b,0,nRead); K3iQ/j~aq
} ~1&WR`U
catch(Exception e){e.printStackTrace ();} Ew JNpecX
} 3rY\y+m
} T&4f}g/
Z(XohWe2
3 "iBcsLn
//打印回应的头信息 "AP$)xM-:
public void logResponseHead(HttpURLConnection con) )Dp0swJ
{ B@U'7`v
for(int i=1;;i++) q BIekQT
{ \n`/?\r.z
String header=con.getHeaderFieldKey(i); PthgxB^
if(header!=null) B! P/?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +e,c'.
Utility.log(header+" : "+con.getHeaderField(header)); l,*5*1lM
else Wu"1M^a
break; as(/ >p
} >=4('
} J5(^VKj
R@-x!*z
/xSFW7d1
public void splitterStop() @QMy!y_K~m
{ '55G:r39
bStop = true; I~;w Q
} { V)`6
2M*i'K;;)P
58d[>0Xa[g
} \wDL oR
zW\s{
fTso[r:F.
/* 7=D,D+f
**FileAccess.java ,5x#o
*//文件访问(定位，写) S@'%dN6e
package NetFox; `{|w*)mD
import java.io.*; L6ap|u
SK#&%Yk
\%7fm#z6
public class FileAccessI implements Serializable{ Y]7503J
qX*xQA|ak,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 wTD}c1J(
RandomAccessFile oSavedFile; RRXp9{x`
long nPos; 51u\am'T
L9<\vJ
?;_*8Doq-a
public FileAccessI() throws IOException 1BEs> Sm
{ '$c9S[
this("",0); r6nnRN/S=
} :w-:B^VB
+TyN;e
P@keg*5@
public FileAccessI(String sName,long nPos) throws IOException |;7mDhj=
{ lWecxD$
oSavedFile = new RandomAccessFile(sName,"rw"); yVgC1-8i*
this.nPos = nPos; T9I$6HAi
oSavedFile.seek(nPos); ]BUirJ,2
} <=V{tl
@TQ/Z$y
MI'"Xzp{s
public synchronized int write(byte[] b,int nStart,int nLen) 4=ovm[
{ ,zdGY]$
int n = -1; i!RfUod
try{ lm 96:S
oSavedFile.write(b,nStart,nLen); S2e3d
n = nLen; _3:%b6&Pz
} ]'"Sa<->
catch(IOException e) 641P)
{ 71y{Dwya
e.printStackTrace (); l -xc*lC
} x1?mE)n]
_U}vKm
K2yu}F^}
return n; hHhDs>tB
} p#{y9s4h
9=~ZA{0J
?].MnwYo
} p0WUF\"
ccrWk*tr
) $_1U!z
/* [gpO?'~
**SiteInfoBean.java D;NL*4zt
*/ F3EAjO)ch
package NetFox; Uns%6o
Z[OX{_2]K
PMpq>$6b7
public class SiteInfoBean { 3i7EF.
F_(~b
s*[ I"iE
private String sSiteURL; //Site's URL .whi0~i
private String sFilePath; //Saved File's Path uE41"?GS
private String sFileName; //Saved File's Name In^mE(8YO
private int nSplitter; //Count of Splited Downloading File >7PQOQMW'
MzX&|wimb
=T,Q7Dh
public SiteInfoBean() 9-/q-,
{//nSplitter的缺省值为5 aTTkj\4
//default value of nSplitter is 5 RARA_tii
this("","","",5); 50QDqC-]XS
} ,puoq{
5, ,~k=
BLyV~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) NX,m6u
{ v>#Njgo
sSiteURL= sURL; `VKFA<T
sFilePath = sPath; b9RHsr]V
sFileName = sName; }q`9U!v
this.nSplitter = nSpiltter; X'jyR:ut#
<@"rI>=
%*}rLn"?
} Yr/$92(
T2MC`s|`
)b #5rQ
public String getSSiteURL() o 2Nu@^+
{ [M[<'+^*
return sSiteURL; 8Y.qP"s
} v*?8:>:}
JFVx&
6[3Xe_
public void setSSiteURL(String value) /iFn=pk1?
{ ANFes*8j
sSiteURL = value; IQ@9S
} q* p
Q-'j131[
!xfDWbvHV
public String getSFilePath() #\w N2`" W
{ .Qx5,)@9
return sFilePath; M5ZH6X@5
} x.*^dM@V
KsP2./N
<E4(KE
public void setSFilePath(String value) Tse#{
{ GIM/T4!)
sFilePath = value; q$:7j5E
} a#=d{/ab
Y7.+ Ma#|
`s}L3bR]
public String getSFileName() iz#R)EB/g
{ N!(mM;1X)
return sFileName; o>r P\
} &T,|?0>~=J
ZOEe-XW
E+lR&~mK=
public void setSFileName(String value) EwzR4,r\M
{ KVa{;zBwl
sFileName = value; &))d],tJX
} YCD|lL#
%]_: \!
7HDc]&z
public int getNSplitter() HLW_Y|QaFo
{ 'z. GAR
return nSplitter; $Y|OGZH8E
} |reA`&<q
!FL"L 9
;#85 _/
public void setNSplitter(int nCount) ojy^A
{ R'k`0
nSplitter = nCount; >J7slDRo
} FMVAXOO
} lV$JCNe
=HCEUB9Fs
B-MS@<2
/* ,a{85HLr]
**Utility.java rkjnw@x\
*/ 5G`HJ6
package NetFox; hI:.Qp`r
']1n?K=A
l;iU9<~
public class Utility { mH$tG $
<Q~N9W
r@4A%ql<
public Utility() t(#9.b`W)
{ ?XHQdN3e
e]RzvWq
a<<4gXx
} ]@#9B>v=
|fgUW.
//线程睡眠 \_`qon$9
public static void sleep(int nSecond) )%K<pIk
{ !zX()V
try{ L+8ar9es
Thread.sleep(nSecond); INN}xZ
} L]kBY2c
catch(Exception e) |Mb{0mKb
{ lcdhOjz!N
e.printStackTrace (); {$^'oRk
} Vgm'&YT
} IEhD5?
|8k1Bap`z
//日志 = wD#H@h
public static void log(String sMsg) /Q;wz!V$
{ q6>eb
System.err.println(sMsg); L BbST!
} hTtn /j
JY"jj}H]|
#d@wjQ0DW
public static void log(int sMsg) 2<@2_wSJ
{ f;{Q ~
System.err.println(sMsg); 1CB&z@
} 3+6Ed;P
} J#(AX6
v&d1ACctJ
5%I3eL%s
/* $,}jz.R@
**TestMethod.java R(wUu#n$
*/ OXEEpoU?V
package NetFox; ^lHy)!&A
<o%T]
t8*Jdd^3Z/
public class TestMethod { %zcA|SefP
e(t}$Q=
8FuxN2
public TestMethod() ).71gp@&
{ ///xx/weblogic60b2_win.exe iww/s
try{ tJ^p}yxO
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Hm2Y% 4i%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1[!:|=
SiteFileFetch fileFetch = new SiteFileFetch(bean); g6,DBkv2
fileFetch.start(); |[.-pA^
} sy"}25s
catch(Exception e){e.printStackTrace ();} 3k1e
dVbFMQ&
1@|+l!rYF
} j.q}OK
3uuIISK
m{Q #f\<
public static void main(String[] args) ,Pa*; o\
{ X!]v4ma`
new TestMethod(); 9nG^_.}|
} 2o SM|
} /7UvV60
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