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)); t `kui.
} g%nl!dgS
for(int i=0;i<nEndPos.length-1;i++) h6~$/`&]b
{ _n;;][]S
nEndPos = nStartPos[i+1]; bQ'8SCe
} 58 bCUh#uw
nEndPos[nEndPos.length-1] = nFileLength; pav'1d%
} 9QQyl\
} - e"jw#B
\$sjrqKnu
rG}\Zjn{
//启动子线程 Hnk:K9u.B:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; _8,()t'"
for(int i=0;i<nStartPos.length;i++) En{`@JsM
{ ag-f{UsTy
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3ZEB
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), */:uV B,b2
nStartPos,nEndPos,i); 3cdTed-MIh
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #>lG7Ns|4
fileSplitterFetch.start(); _{<seA
} &i+Ce
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), El\%E"Tk%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0:w"M<80
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", SZaS;hhhHu
nEndPos = " + nFileLength); ?POUtRN
// fileSplitterFetch[nPos.length-1].start(); |L2SFB?d=
,XDRO./+T
7frTTSZ
//等待子线程结束 wE+${B03
//int count = 0; n3AaZp[
//是否结束while循环 A,sr[Pa@
boolean breakWhile = false; 8Nu=^[qwQM
`]Q:-h
$9Hcdbdm
while(!bStop) ;rc`OZyE
{ UMAgA!s
write_nPos(); [!!Q,S"
Utility.sleep(500); /|* Y2ETOr
breakWhile = true; 93Co}@Y;Y+
o2<#s)GpY
:oJ=iB'Zc
for(int i=0;i<nStartPos.length;i++) 'Ut7{rZ5
{ hjZKUMG(k
if(!fileSplitterFetch.bDownOver) 'yMF~r3J
{ Z&;uh_EC
breakWhile = false; vZ.x{"n'~
break; <HbcNE~
} ``wSc0\
} s"t$0cH9
if(breakWhile) >=[(^l
break; }Y;K~J
gNt(,_]ZR
ZYC<Wb)I
//count++; 1t)il^p4[;
//if(count>4) `@nl
// siteStop(); Q ]}Hd-
} Lhqz\o
Y1]n^
rqY`8Ry2M
System.err.println("文件下载结束！"); #Y$hNQQ$F
} ?Y@N`S
catch(Exception e){e.printStackTrace ();} dq]0X?[6
} rzt Ru
ZIQ [bE7
hEp(A8g)bQ
//获得文件长度 uD^cxD
public long getFileSize() yU9DSY\m{
{ Z<vKQ4G
int nFileLength = -1; tCdqh-
try{ c@893<_
URL url = new URL(siteInfoBean.getSSiteURL()); Y'8?.a]'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9jw\s P@
httpConnection.setRequestProperty("User-Agent","NetFox"); V,cBk
+F^^c2E
\--8lH -K
int responseCode=httpConnection.getResponseCode(); 3.*8)NW
if(responseCode>=400) ))"6ern
{ g"}%2~Urf
processErrorCode(responseCode); ~^1{B\I
return -2; //-2 represent access is error ,%M$0poKM
} [5SD_dN
t+!$[K0/
MB]<Dyj,
String sHeader; ;IZwTXu!S
T(U_
E>D_V@,/
for(int i=1;;i++) 0"f\@8r(
{ 7t0er'VC
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); % ~H=sjg
//Utility.log(in.readLine()); ~kEI4}O
sHeader=httpConnection.getHeaderFieldKey(i); 7_inJ$
if(sHeader!=null) oYm[V<nIl
{ |l]XpWV
if(sHeader.equals("Content-Length")) ^LoUi1j
{ a6)BqlJ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Yfzl%wc
break; %z,mB$LY
} $#9;)8J
} T?ZRiR)@
else h7lDHIQf
break; {#?N
} vunHNHltW0
} ix)M`F%P3
catch(IOException e){e.printStackTrace ();} 4NheWM6
catch(Exception e){e.printStackTrace ();} 5YeM%%-S
,9zjFI
r\'A i6
Utility.log(nFileLength); W{6|tx)
EyJJ0
4;yKOQD|
return nFileLength; keL&b/@
} !>..Q)z
eD?tLj
k@RDvn
//保存下载信息（文件指针位置） 8]/bK5`
private void write_nPos() _E@2ZnD2
{ hKL4cpK4
try{ f!Y?S
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5YE'L.
output.writeInt(nStartPos.length); DgId_\Ze
for(int i=0;i<nStartPos.length;i++) sBvzAVBL
{ .WA-&b_
// output.writeLong(nPos); qr"3y
output.writeLong(fileSplitterFetch.nStartPos); `T@i.'X
output.writeLong(fileSplitterFetch.nEndPos); u8&Z!p\
} lb4Pcdj
output.close(); E7j(QOf
} SJb&m-
catch(IOException e){e.printStackTrace ();} N +Yxz;Mg
catch(Exception e){e.printStackTrace ();} jnO9j_CY
} 6F!+T=
xpV|\2C
4&<oFW\r
//读取保存的下载信息（文件指针位置） i[7\[
private void read_nPos() ^}/PGG\~r
{ =Y{(%sn
try{ 89pEfl j2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %g{X?
int nCount = input.readInt(); h7G"G"
nStartPos = new long[nCount]; V_:1EBzz
nEndPos = new long[nCount]; J=9FRC
for(int i=0;i<nStartPos.length;i++) P{kur} T
{ /M1ob:m
nStartPos = input.readLong(); ey7 f9
nEndPos = input.readLong(); +h|`/ &,
} %(3|R@G.
input.close(); +"\sc;6m.
} P+@/O
catch(IOException e){e.printStackTrace ();} t<.)Z-Ii
catch(Exception e){e.printStackTrace ();} n{n52][J]
} dk[!V1x4\
yj 3cyLXw
5d Eh7XL
private void processErrorCode(int nErrorCode) SYAyk
{ Pr':51(
System.err.println("Error Code : " + nErrorCode); Q{sH3Y#l
} #xsE3Wj-X
##,a0s^
&#{Z(h.de
//停止文件下载 V\ZGd+?
public void siteStop() UOv+T8f=
{ k9sh @ENy
bStop = true; XRM_x:+]
for(int i=0;i<nStartPos.length;i++) $v4.sl:x
fileSplitterFetch.splitterStop(); JFcLv=U
>*~L28Fyn
:3v}kLO7|
} ^S4d:-.3
} b[r8e
//负责部分文件的抓取 PCHu#5j_a
**FileSplitterFetch.java DU0zez I9
*/ M'?,] an
package NetFox; ZQ4p(6a
%aG5F}S2~
%".HaI]
import java.io.*; [L3=x;U
import java.net.*; hci6P>h<ia
? &o2st
pA'4|ffwe
public class FileSplitterFetch extends Thread { zqimR#u
cvn@/qBq*t
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String sURL; //File URL dU&a{$ku[
long nStartPos; //File Snippet Start Position <Th6r.#?
long nEndPos; //File Snippet End Position yZ0-wI
int nThreadID; //Thread's ID g!g#]9j
boolean bDownOver = false; //Downing is over jD$,.AVvz
boolean bStop = false; //Stop identical "@e3EX7h
FileAccessI fileAccessI = null; //File Access interface =_.l8IYX$%
dN$0OS`s[
e>} s;H,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Nyku4r0
{ (yH'{6g\
this.sURL = sURL; [^WC lRF
this.nStartPos = nStart; Fco`^kql.D
this.nEndPos = nEnd; {{$Nqn,pH
nThreadID = id; %0S3V[4I
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7x"R3
} +SP{hHa^
nHM~
R5N%e%[
public void run() ]~Rho_mq#
{ JrJo|0Q
while(nStartPos < nEndPos && !bStop) iOd&BB6
{ u(z$fG:g
qk%;on&`
ih58<Up5
try{ 66g9l9wm(
URL url = new URL(sURL); S5gyr&dm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Yz<3JRw
httpConnection.setRequestProperty("User-Agent","NetFox"); u0JB\)(-/h
String sProperty = "bytes="+nStartPos+"-"; UFXaEl}R
httpConnection.setRequestProperty("RANGE",sProperty); B{QBzx1L9c
Utility.log(sProperty); T;Lkaxsn
w#ZoZZ wh
5dx$HE&b)
InputStream input = httpConnection.getInputStream(); -RE^tW*Yy
//logResponseHead(httpConnection); 3atBX5
{ }:#G
1h^:[[!c
byte[] b = new byte[1024]; m]'#t)B_m
int nRead; y*4=c_Z
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :vmH]{R
{ GSoX<*i
nStartPos += fileAccessI.write(b,0,nRead); RVZ")Z(
//if(nThreadID == 1) $h+1u$po
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .T}Wdng
} QVv#fy1"6
P}Gj%4/G
M,j U}yD3
Utility.log("Thread " + nThreadID + " is over!"); aZH:#lUlj
bDownOver = true; bZ dNibN
//nPos = fileAccessI.write (b,0,nRead); @3>u@
} f/U`
catch(Exception e){e.printStackTrace ();} rlMLW
} j b!x:
} mUNn%E:7@{
$jjfC
p\Q5,eg
//打印回应的头信息 BGvre'67
public void logResponseHead(HttpURLConnection con) FI)17i$
{ [@&m4 7
for(int i=1;;i++) %vn|k[nD
{ 'f#{{KA
String header=con.getHeaderFieldKey(i); PIJr{6B/PA
if(header!=null) K%,2=.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); h){0rX@:&
Utility.log(header+" : "+con.getHeaderField(header)); @D]5civm_
else ^ sOQi6pL
break; =J18eH!]
} E~DQ-z
} uu-PJTNZ
-"R2
#Vnkvvv
public void splitterStop() ;!>rnxB?4
{ J!AgBF N4
bStop = true; I&fozO
} U&g@.,Y#
$POu\TO
)cW#Rwu_A4
} gt\E`HB8E
3$9s\<j
O\ GEay2
/* ]tim,7s
**FileAccess.java z{8bvuE
*//文件访问(定位，写) KWq+PeB5TS
package NetFox; B?OFe'*
import java.io.*; o8 IL$:
WO7z
Bj+S"yS
public class FileAccessI implements Serializable{ h8x MI
AgWa{.`f:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &9.Cl;I
RandomAccessFile oSavedFile; WEw6He;
long nPos; ,cXD.y
=%BSKSG.
a]$1D!Anc
public FileAccessI() throws IOException j:Xq1f6a
{ yjO1 Ol
this("",0); .Hescg/S
} c_dVWh e
zKyyU}LHH
YC*"Thuu
public FileAccessI(String sName,long nPos) throws IOException w0[6t#$F
{ ZFA`s qT
oSavedFile = new RandomAccessFile(sName,"rw"); *2ZjE!A
this.nPos = nPos; [xbSYu,&
oSavedFile.seek(nPos); {yBs7[Wn
} 1m'k|Ka
,[N%Q#
-$t{>gO#Y
public synchronized int write(byte[] b,int nStart,int nLen) T tfo^ksw
{ raW>xOivR
int n = -1; g!|=%(G=
try{ k 9_`(nx
oSavedFile.write(b,nStart,nLen); $CRm3#+ ~
n = nLen; <KJ/<0l
} ,A9]CQ
catch(IOException e) 3BzNi'
{ !-g{[19\
e.printStackTrace (); ]dF ,:8
} D+#E-8
*-#&K\
Ij 79~pn
return n; rExnxQ<e
} #?RU;1)Cw
2\R'@L*
_1!7V3|^
} xn?a. 3b'
m1j*mtu
QpF;:YX^3
/* vXev$x=w-
**SiteInfoBean.java DMs,y{v
*/ b k~(^!R
package NetFox; N(O9&L*4fm
_;W.q7b]
{k(g]#pP
public class SiteInfoBean { hMa]B*o/-
y>S.?H:P
?#Ge.D~u
private String sSiteURL; //Site's URL x" 7H5<
private String sFilePath; //Saved File's Path |a8iZ9/D6
private String sFileName; //Saved File's Name J;S (>c
private int nSplitter; //Count of Splited Downloading File &PL8|w
!:)s"|=
3D6RLu
public SiteInfoBean() Zj_b>O-V
{//nSplitter的缺省值为5 _PPy44r2
//default value of nSplitter is 5 2"COP>
this("","","",5); MO[2~`,Q!
} q~rEq%tk
]yV!
)"qa kT
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R1PkTZP&
{ )tG\vk=@
sSiteURL= sURL; NxfOF
sFilePath = sPath; *=) cQeJ
sFileName = sName; 1kz\IQ{
this.nSplitter = nSpiltter; )z>|4@,
Qo>b*Ku;
@<,X0S
} .28<tEf
YP 6`L
-<6\1J
public String getSSiteURL() } j<)L,
{ ~cWAl,(B<F
return sSiteURL; %Celc#v
} Ii6<b6-
AWcLUe{
5sdn[Tt##
public void setSSiteURL(String value) ?}qttj
{ '|ad_M
sSiteURL = value; y~(h>gi,x
} .nTwPrG
\-L&5x"x
u^&A W$
public String getSFilePath() vjLJinJ/
{ vp1941P
return sFilePath; Mc@e0
} 8."]//V
8<5]\X
rW<KKGsRWQ
public void setSFilePath(String value) +\x,HsUc"
{ [2>yYr s_=
sFilePath = value; U] ~$g}!)
} (DJ"WG
FSP+?((
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public String getSFileName() 9K.Vb1&
{ 1Vsz4P"O $
return sFileName; A_V]yP
} ]E7F/O/.
3^IpE];+:u
Gq+z/Be
public void setSFileName(String value) f W!a|?e$
{ !]42^?GH
sFileName = value; Ha(c'\T(\
} ^/)^7\@
d^@dzNv
I?]ohG K
public int getNSplitter() @#<D ^"
{ Wfu(*
return nSplitter; '>NCMB{*
} 7jxslI&F
?:pP8/y
0\H\lKcK
public void setNSplitter(int nCount) |<HPn4 ,X
{ wYdb*"R
nSplitter = nCount; [I0:=yJ+
} \?w2a$?6w
} !6n_}I-W
l#m#c6;=
vV6<^W:9F
/* s0\X ^
**Utility.java ? 8)'oMD
*/ `V=N*hv`
package NetFox; @V(*65b2
t=rEt>n~L
t;\kR4P
public class Utility { 81](T<
bG7O
cq5jPZ}
public Utility() 1G"z<v B
{ ;}7Rjl#
E08klC0
>x/z7v?^I
} WM Fb4SUR
C`K?7v3$m
//线程睡眠 nv GF2(;l
public static void sleep(int nSecond) 4<9=5q]
{ BYpG
try{ _?<|{O
Thread.sleep(nSecond); ,qA(\[
} ^.1)};i
catch(Exception e) ={_C&57N1
{ #~#R-
e.printStackTrace (); ~F7-HaQJ
} uYn_? G
} zxJ]"N
wi;Br[d
//日志 6{x(.=
public static void log(String sMsg) ,kF1T,
{ ]|!OP
System.err.println(sMsg); F{Z~ R
} }e!x5g
N+++4;
! _f9NK
public static void log(int sMsg) YT8vP~
{ 5}:-h>
System.err.println(sMsg); ?u-|>N>
} PbW(%7o(t
} 7/!8e.M\
'r4/e-`pK
]*vdSr-J
/* j`oy`78O
**TestMethod.java tU4s'J
*/ 3XL#0\im?s
package NetFox; Qr1"Tk7s
~Am,%"%\
Cf TfL3(J
public class TestMethod { H+1-]'g`
5pj22 s
E'G4Y-
public TestMethod() N8k00*p65
{ ///xx/weblogic60b2_win.exe Hcl(3>Jn2
try{ K$>%e36Cc
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +s(HOq)b
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &]8P1{
SiteFileFetch fileFetch = new SiteFileFetch(bean); H!?c\7adX
fileFetch.start(); U@g4w!$r
} Jzj1w}?H
catch(Exception e){e.printStackTrace ();} M1 :uJkO.
b8~Bazk
u&`XB|~
} sA/pVU
?h.wK
$@"l#vJPfc
public static void main(String[] args) os,* 3WO
{ y603$Cv
new TestMethod(); IHe/xQ@
} $8;R[SU6Y
} ~T9/#-e>BF
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