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)); <AoXEuD
} @n+=vC.xO
for(int i=0;i<nEndPos.length-1;i++) ?cy4&]s
{ @It>*B yB.
nEndPos = nStartPos[i+1]; #,NvO!j<4
} z=Cr7-
nEndPos[nEndPos.length-1] = nFileLength; mUoIJ3fv_,
} 5:.{oSy7n
} =O$M_1lp
|j~lkzPnV
~bK9R0|<
//启动子线程 p&b5% 4P
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; PnYBy| yl
for(int i=0;i<nStartPos.length;i++) H17-/|-;0!
{ 7'lZg<z{~j
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2kh"8oQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), m#7*:i&@Y
nStartPos,nEndPos,i); }6u2*(TmD
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8|^CK|m6*
fileSplitterFetch.start(); {*m?Kc7k
} SPkn3D6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ipE]}0q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); MXtkP1A`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3'`dFY,
nEndPos = " + nFileLength); ??&<k
// fileSplitterFetch[nPos.length-1].start(); 3G}AH E4
5Wx~ZQZ
aHzHvl
//等待子线程结束 wq!iV |
//int count = 0; q(M:QWA q
//是否结束while循环 <%?#AVU[
boolean breakWhile = false; o4y']JSN
~FU@wV^
d^E [|w;
while(!bStop) j]rz]k
{ uBrMk
write_nPos(); DGESba\2+
Utility.sleep(500); ;q>9W,jy
breakWhile = true; zCaT tb|@
XzIx:J6
=n(3o$r(
for(int i=0;i<nStartPos.length;i++) TI|/u$SJ<Z
{ PJ4(}a
if(!fileSplitterFetch.bDownOver) @~td`Z?1y
{ *Mc7f?H
breakWhile = false; 0MF}^"R
break; c]k*}W3T
} _QOZsEe
} $.%rAa_H
if(breakWhile) AnBJ(h
break; G\d$x4CVGc
I0'WOV70
4'1m4Ugg
//count++; !U%T&?E l
//if(count>4) KJn!Ap
// siteStop(); e.d #wyeX
} bpAv1udX-W
W!Gdf^Yy<
(.Y/
System.err.println("文件下载结束！"); T#@lDpO
} y[};J vk
catch(Exception e){e.printStackTrace ();} K>:]Bx#F7
} xgu `Q`~
cf_|nL#9
#18FA|
//获得文件长度 d~J-|yyT
public long getFileSize() OWp%v_y]
{ B5%n(,Lx
int nFileLength = -1; <6TT)t<h
try{ 2-*V=El
URL url = new URL(siteInfoBean.getSSiteURL()); q/9H..6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^ <`(lyph
httpConnection.setRequestProperty("User-Agent","NetFox"); Jb_1LZ)]
`O?T.p)
Uh eC
int responseCode=httpConnection.getResponseCode(); oTjyN\?H
if(responseCode>=400) 2NGeC0=
{ E_z;s3AXQ
processErrorCode(responseCode); uQ$^;Pr
return -2; //-2 represent access is error #65^w=Sp}
} ? 8aaD>OR$
B_`y|sn
~T7B$$
String sHeader; +gd2|`#
NH<gU_s8{9
qVqRf.-\
for(int i=1;;i++) u|#>32kV
{ /&#XhrT
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); lA(Q@yEW
//Utility.log(in.readLine()); $q?$]k|M`
sHeader=httpConnection.getHeaderFieldKey(i); Wm~` ~P
if(sHeader!=null) lH^^77"4Qo
{ %.v{N6
if(sHeader.equals("Content-Length")) DhLqhME53
{ 85:NFa@J
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %sBAl.!BN
break; &.13dq
} s'aip5P
} wFh8?Z3u_
else [D"t~QMr
break; Y}*\[}l:&x
} 'nQVj
} o{b=9-V
catch(IOException e){e.printStackTrace ();} EJ}!F?o
catch(Exception e){e.printStackTrace ();} N]EcEM#
-{XRA6
O`GsS{$sS
Utility.log(nFileLength); l- pe4x
s&kQlQ=
5<pftTcZ
return nFileLength; kv,%(en]
} mP38T{
Jb)#fH$L
YYEJph@06q
//保存下载信息（文件指针位置） lE8&..~l$+
private void write_nPos() qSqI7ptA\
{ keW~ NM
try{ PP~rn fE
output = new DataOutputStream(new FileOutputStream(tmpFile)); -4rDbDsr
output.writeInt(nStartPos.length); kd:$oS_*s
for(int i=0;i<nStartPos.length;i++) 1be %G [*
{ 1axQ)},o@p
// output.writeLong(nPos); Ab%;Z5$fr
output.writeLong(fileSplitterFetch.nStartPos); jCAC `
output.writeLong(fileSplitterFetch.nEndPos); 4(neKr5\#
} r)9Dy,
output.close(); unJid8Lo
} 87%*+n:?*
catch(IOException e){e.printStackTrace ();} EpS(o>'
catch(Exception e){e.printStackTrace ();} jc[_I&Oc_
} +x?#DH-
$8USyGi3J
aV o;~h~
//读取保存的下载信息（文件指针位置） *%w69#D
private void read_nPos() Ut-B^x)gl
{ U-k+9f 0
try{ UX3BeUi.)
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,:fl?x.X
int nCount = input.readInt(); $&s=68
nStartPos = new long[nCount]; [3l*F
nEndPos = new long[nCount]; CM)Q&:
for(int i=0;i<nStartPos.length;i++) g*)K/Z0pJ$
{ zl-2$}<a
nStartPos = input.readLong(); cfox7FmW
nEndPos = input.readLong(); K3uG2g(>2
} oRKEJNps
input.close(); KIA 2"KbjG
} jV#ahNq;
catch(IOException e){e.printStackTrace ();} n?\ nn3
catch(Exception e){e.printStackTrace ();} Mypc3
} &R|/t:DN
M<SdPC(+
&1l=X]%
private void processErrorCode(int nErrorCode) IKMeJ(:S
{ WwF~d+>|C
System.err.println("Error Code : " + nErrorCode); )15Z#`x
} ONNpiK-
,:~0F^z
{U 'd}Q
//停止文件下载 4Wy<?O2
public void siteStop() IX: 25CEI2
{ 2)#K+O3c
bStop = true; ms($9Lv/
for(int i=0;i<nStartPos.length;i++) ~^u16z,
fileSplitterFetch.splitterStop(); Wk:hFHs3
^JI o?R
i,V;xB2
} nJRS.xs
} ^l^fD t
//负责部分文件的抓取 J$4wL F3
**FileSplitterFetch.java R1F5-#?'E
*/ {7!UQrm<
package NetFox; `r5$LaD
T5Q{{@Q
+,:du*C
import java.io.*; c`lJu_
import java.net.*; (>mI'!4d
t E` cau
/&u<TJ4
public class FileSplitterFetch extends Thread { N=:5eAza
Wv__ wZ
`28};B>
String sURL; //File URL VIP7OHJh
long nStartPos; //File Snippet Start Position G*S|KH
long nEndPos; //File Snippet End Position @)kO=E d
int nThreadID; //Thread's ID DjU9 uZT
boolean bDownOver = false; //Downing is over SVjl~U-^
boolean bStop = false; //Stop identical ,+qVu,
FileAccessI fileAccessI = null; //File Access interface 22kpl)vbU
WwC 5!kZ
2([2Pb3<"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException w;Q;[:y
{ cPgfTT
this.sURL = sURL; 2&+#Vsm`V
this.nStartPos = nStart; Auy_K?he]
this.nEndPos = nEnd; T081G`li
nThreadID = id; J7C4V'_
fileAccessI = new FileAccessI(sName,nStartPos);//定位 P5lqSA{6
} r]W
Oz|K8p
79\JxiSB
public void run() zkTp`>9R
{ |IunpZV
while(nStartPos < nEndPos && !bStop) %{3 aW>yx
{ awvDe
nR4y`oP+
tb:L\A^:
try{ l5+gsEux]
URL url = new URL(sURL); ?ER-25S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {]z4k[;.h
httpConnection.setRequestProperty("User-Agent","NetFox"); 9}B`uJ
String sProperty = "bytes="+nStartPos+"-"; /(O$(35
httpConnection.setRequestProperty("RANGE",sProperty); gPAX4'
Utility.log(sProperty); {;2vmx9
]"c+sMW
USN8N (
InputStream input = httpConnection.getInputStream(); }HE6aF62O
//logResponseHead(httpConnection); sC[yI Up
JFgoN,xn
{0! ~C=P
byte[] b = new byte[1024]; bYz&P`o}
int nRead; =AVgIv
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~&\ f|%
{ a[lY S{
nStartPos += fileAccessI.write(b,0,nRead); x8;`i$
//if(nThreadID == 1) '0$?h9"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b3wM;jv
} {JV@"t-X3"
o]IjK
IVr 2y8K
Utility.log("Thread " + nThreadID + " is over!"); >NB?&|
bDownOver = true; nm7;ieMfr
//nPos = fileAccessI.write (b,0,nRead); H:p Z-v*
} fYE(n8W3
catch(Exception e){e.printStackTrace ();} i{D=l7j|w
} +GsWTEz
} jGrN\D?h
B2Xn?i3 l
@"T"7c?Cv
//打印回应的头信息 i(?,6)9
public void logResponseHead(HttpURLConnection con) FgL,k
{ +n}$pM|NKU
for(int i=1;;i++) PSawMPw
{ ;n\= R 5.
String header=con.getHeaderFieldKey(i); Y!6/[<r$~k
if(header!=null) s4_/&h
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?PTk1sB
Utility.log(header+" : "+con.getHeaderField(header)); _LwOOZj
else vIvVq:6_3
break; EQqx+J&!
} kY]W Qu
} PpLU
[sW.CK=3
Og;-B0,A
public void splitterStop() EBtLzbj
{ yfU<UQ!1
bStop = true; Yxv9
} = 07Gy,=i
(;VVCAoy
`Q+moX
} kj+#TnF-
VL[)[~^
gPC*b+
/* LJX-AO.4
**FileAccess.java :Q+5,v-c
*//文件访问(定位，写) I ];M7
package NetFox; ylKmj]A
import java.io.*; 9+,R`v
1Y_w5dU
X0{/ydGF8
public class FileAccessI implements Serializable{ 1_$xSrwcF
nN$Y(2ZN
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8Ry74|`=R
RandomAccessFile oSavedFile; 5>6PH+Oq
long nPos; M5T9JWbN
xoB},Xl$D
k%[3Q>5iM
public FileAccessI() throws IOException xUF_1hY
{ %AF5=
this("",0); ,wKe fpV;5
} "l={)=R
vaf&X]p
)'l*Tl
public FileAccessI(String sName,long nPos) throws IOException 1>Q{Gs^
{ b]E|*
oSavedFile = new RandomAccessFile(sName,"rw"); ?)'~~@NkH
this.nPos = nPos; 39{{7(hh
oSavedFile.seek(nPos); B7\k< Nit0
} k7tYa;C
.^)UO
2!N8rHRt
public synchronized int write(byte[] b,int nStart,int nLen) J==SZ v
{ Oo?,fw
int n = -1; 2/,0iwj-
try{ %hlspI(J
oSavedFile.write(b,nStart,nLen); M>jtFP<S
n = nLen; 3Q/#T1@
} {;2i.m1
catch(IOException e) $-+/$!
{ ~-a'v!
e.printStackTrace (); wPbkUVO
} #6Xs.*b5C
P7B:%HiAx
Qy#)Gxp
return n; wV?,Z!\Z
} ~.PP30'
GFSt<k)
[NnauItI
} `SO|zz|'
M(|
S{',QO*D6
/* G0n'KB
**SiteInfoBean.java >#+IaKL7
*/ _<ut)G^9
package NetFox; g%[n4
/8@m<CW2Y
J H.K.C(
public class SiteInfoBean { EoX_KG{
dQy>Nmfy
wx=0'T-[
private String sSiteURL; //Site's URL =1dI>M>tm
private String sFilePath; //Saved File's Path 5)1+~B
private String sFileName; //Saved File's Name ^EVc95|Z
private int nSplitter; //Count of Splited Downloading File {Hr$wa~
wLuv6\E
_eLWQ|6Fx
public SiteInfoBean() 59(U`X
{//nSplitter的缺省值为5 QD{:vG g
//default value of nSplitter is 5 `h;k2Se5
this("","","",5); 9^P2I)aD
} !BU)K'mj
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nW\(IkX\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;%J5=f%z)
{ R)!`JKeO/
sSiteURL= sURL; t?;T3k[RM
sFilePath = sPath; 4X NxI1w)
sFileName = sName; [%HIbw J
this.nSplitter = nSpiltter; ,]R8(bD)
WUAJjds
fbZibcQ%k
} OH<?DcfeL
IL7`0cN(
jW*1E*"
public String getSSiteURL() 'f?.R&sCA
{ JU0]Wq<^[
return sSiteURL; %R_{1GrL'c
} [n,?WwC
EruP
,KW;2t*IQ@
public void setSSiteURL(String value) :lcea6iO
{ 9T2xU3UyY
sSiteURL = value; ?y},,
} (k-YI{D3
uK*Nu^
BpAB5=M0
public String getSFilePath() B7NtkMK
{ Z\X'd_1!
return sFilePath; qZ2&Xw.{1
} Bt^K]F\
~>ME'D~
%@&a7JOL
public void setSFilePath(String value) {I%y;Aab8
{ jigs6#
sFilePath = value; Iyk6=&?j
} LR)& [{Kk
U`R;P-
Ru%|}sfd
public String getSFileName() `ZHP1uQ<
{ <v]9lw'
return sFileName; E|Bd>G
} $]d*0^J 6
^Uw[x\%#gD
T!q_/[i~7
public void setSFileName(String value) o|S)C<w
{ <MD;@_Nz\
sFileName = value; ru.5fQU
} 74vmt<Q
NlR"$
:x>T}C<Y
public int getNSplitter() #Olg(:\
{ <SXZx9A!
return nSplitter; H^c0Kh+
} X\GM/A
fhpX/WE6
V: p)m&y6
public void setNSplitter(int nCount) gqiXmMm:9
{ _pDjg%A>n
nSplitter = nCount; =(U/CI
} K\=8eg93Z
} -R+zeu(e'
;'kI/(;;C
T@+ClZi
/* OS7RQw1
**Utility.java 10N,?a
*/ B< ;==|
package NetFox; a#(U2OP
=TcOnQj
ki\uTD`mf
public class Utility { 3l:QeZ
/J%do]PDl
2YQ#-M
public Utility() vb=CFV#
{ VZxTx0: ,
~^o=a?L`<
_,;%mK
} o\4t4}z~'f
_'iDF
//线程睡眠 HFh /$VM
public static void sleep(int nSecond) l)}t,!M6
{ b;vNq
try{ /5a;_
Thread.sleep(nSecond); tjzA)/T,4
} }OKL z.5
catch(Exception e) XCPb9<L
{ '"O&J}s;
e.printStackTrace (); `"<2)yq?
} p]f&mBO*
} MQw9X
u^Sv#K X
//日志 }""p)Y&
public static void log(String sMsg) XeUprN
{ 8fO8Dob]\Y
System.err.println(sMsg); XL"=vbD
} v&0d$@6/U
|^5/(16
az(5o
public static void log(int sMsg) i.@*tIK
{ _EKF-&Q6
System.err.println(sMsg); c cr" ep
} zGs|DB
} z[#6-T &
# cWHDRLX
+{>.Sk'$
/* _"f<Ol[!
**TestMethod.java <q6`~F~|
*/ 0/A-#'>
package NetFox; 2ij/N%l
R7K
wXCyj+XB*
public class TestMethod { {visv{R<
}u^:MI
-N^=@Yx)
public TestMethod() ' o=E!?
{ ///xx/weblogic60b2_win.exe ~I)uWo
try{ @a;sV!S{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9/46%=&]
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); d=nh
SiteFileFetch fileFetch = new SiteFileFetch(bean); cyc>_$/;1
fileFetch.start(); sFx$>:$
} %Rn:GK
catch(Exception e){e.printStackTrace ();} z\$;'
)kA2vX^=Z
59MR|Jt
} cju@W]!
\]a uSO
PJwEA
public static void main(String[] args) .HDebi
{ "o==4?*L
new TestMethod(); =tq7z =k
} Lw*1 .~
} {{zua-F
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