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)); *6aIDFNl
} \P;2s<6i\
for(int i=0;i<nEndPos.length-1;i++) :pdl2#5H^
{ 85_Qb2<'r
nEndPos = nStartPos[i+1]; (3?W)i
} n.7-$1
nEndPos[nEndPos.length-1] = nFileLength; &&ZX<wOM
} rlQ=rNrG&E
} )Ah7
LUzn7FZk
2GxkOch
//启动子线程 Z 5 Xis"j
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0=k
for(int i=0;i<nStartPos.length;i++) 1\Z/}FT
{ E1D0un
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /8wfI_P>M"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), X$*]$Ge>
nStartPos,nEndPos,i); K/0Wp %
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L./{^)
fileSplitterFetch.start(); ML.|\:r*
} ]P>c{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0{(5J,/BF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); oTg 'N
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", dC>(UDC
nEndPos = " + nFileLength); ,Bs/.htQj
// fileSplitterFetch[nPos.length-1].start(); tz9"#=}0
tu's]3RE
abw5Gz@Ag
//等待子线程结束 6w4HJZF~
//int count = 0; )lU9\"?o
//是否结束while循环 @^.o8+Pp
boolean breakWhile = false; 30W.ks5(
WOQ>]Z
E?FUr?-[
while(!bStop) TPn#cIPG
{ PsM8J
write_nPos(); 3qkPe_<I
Utility.sleep(500); & zv!cf
breakWhile = true; ?4#UW7I
p"0Dl9
dVSQG947i:
for(int i=0;i<nStartPos.length;i++) Pq,iR J
{ ~?:>=x
if(!fileSplitterFetch.bDownOver) H 3so&_
{ =~TPrO^
breakWhile = false; W[:CCCDL
break; `<-/e%8
} <k 'zz:[c!
} s6k(K>Pl
if(breakWhile) S1#5oy2
break; c8Nl$|B
7c!#e=W@B
owx0J,,G
//count++; ?}U?Q7vx@@
//if(count>4) w:ASB>,!
// siteStop(); ZgfhNI\
} O1!YHo
mD%IHzbn H
[Z^26/5a
System.err.println("文件下载结束！"); sB5@6[VDI
} gs&F .n
catch(Exception e){e.printStackTrace ();} nrR2U`
} 6mqp`x`
K >Q6
OAaLCpRp
//获得文件长度 Dq-[b+bm
public long getFileSize() &W3Hj$>
{ 49ehj1Se
int nFileLength = -1; WmkCV+thA
try{ cRE6/qrXGg
URL url = new URL(siteInfoBean.getSSiteURL()); kGAB'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mqbCa6>_S
httpConnection.setRequestProperty("User-Agent","NetFox"); R$`%<Y3)
xDNXI01o
@hwNM#>`
int responseCode=httpConnection.getResponseCode(); -2j[;kgt}
if(responseCode>=400) {Wndp%
{ j`#H%2W\;
processErrorCode(responseCode); %Fx^"
return -2; //-2 represent access is error yqH9*&KH{
} g_JQW(_
gvr&7=p
u$FL(m4
String sHeader; % s@
#/5eQTBD
vdigw.=z
for(int i=1;;i++) qHvU4v
{ V.ETuS;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Et y?/
//Utility.log(in.readLine()); Ezev ^O]
sHeader=httpConnection.getHeaderFieldKey(i); G#ELQ/Q
if(sHeader!=null) _St":9'uU
{ kek/C`7
if(sHeader.equals("Content-Length")) NLu[<u U*
{ JXHf$k
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); P/xEn_*v
break; uAs!5h
} (b.4&P"0
} 8@b`a]lgrd
else putRc??o;
break; ui-]%~
} x.$cP
} ttls.~DG
catch(IOException e){e.printStackTrace ();} >f4[OBc
catch(Exception e){e.printStackTrace ();} i(;.Y
6uTC2ka[&R
U2LD_-HZ
Utility.log(nFileLength); rGrR;
V`9*_8Dx2
fhyoSRLR:
return nFileLength; FzykC
} QNXoAx%I
_.E{>IFw
9GsG*$-I
//保存下载信息（文件指针位置） f^KN8N
private void write_nPos() xm5?C>vu(
{ +d?|R5{3
try{ t/_\w"
output = new DataOutputStream(new FileOutputStream(tmpFile)); +Jm vB6s
output.writeInt(nStartPos.length); ^nK7&]rK
for(int i=0;i<nStartPos.length;i++) DWEDL[{
{ e1y#p3 @d
// output.writeLong(nPos); 7w]3D
output.writeLong(fileSplitterFetch.nStartPos); N|%r5%
output.writeLong(fileSplitterFetch.nEndPos); "G,,:H9v
} :iGK9I
output.close(); ,N;2"$+E
} fP6\Ur
catch(IOException e){e.printStackTrace ();} =M}tet }
catch(Exception e){e.printStackTrace ();} It<VjN9
} [#YzU^^Ib
e"*1l>g
=>kg]
//读取保存的下载信息（文件指针位置） 4GH&u,
private void read_nPos() +XSe;xk;rD
{ A@Lr(L
try{ ?!<Q8=
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7yXJ\(6R_
int nCount = input.readInt(); F'F6 &a+
nStartPos = new long[nCount]; 5;G0$M0
nEndPos = new long[nCount]; }/#*opcv
for(int i=0;i<nStartPos.length;i++) &['L7
{ Bp@\p)P(
nStartPos = input.readLong(); &,3s2,1U(
nEndPos = input.readLong(); |i~-,:/-Y
} LwTdmR
input.close(); /n6ZN4
} 8TG|frS
catch(IOException e){e.printStackTrace ();} UG_PrZd
catch(Exception e){e.printStackTrace ();} D?UURURf
} W /*?y&
2(x| %
sCP|d`'
private void processErrorCode(int nErrorCode) :R3iLy
{ z}B8&*>
System.err.println("Error Code : " + nErrorCode); {'[VL;k
} V;^N:I\js
FFcIOn
+'+Nr<
//停止文件下载 X y`2ux+>/
public void siteStop() Z:Vde^Ih
{ iz)r.TJ
bStop = true; ]N;nq
for(int i=0;i<nStartPos.length;i++) mq:WBSsV
fileSplitterFetch.splitterStop(); US=K}B=g
zY7M]Az
Q`NdsS2
} :WsHP\r
} /Oi(5?Jn
//负责部分文件的抓取 Z{:;LC
**FileSplitterFetch.java RZKx!X4=q
*/ s$,G5Feub
package NetFox; PIXqd,
"FhC"}N
k}I65 ^l#
import java.io.*; nP<u.{q L
import java.net.*; <L11s%5-
/hmDePo}
~-y&C%
public class FileSplitterFetch extends Thread { {0np
|(2#KMEWa
b:r8r}49
String sURL; //File URL e@;'#t
long nStartPos; //File Snippet Start Position xf8[&?
long nEndPos; //File Snippet End Position $E[M[1j
int nThreadID; //Thread's ID AWPgrv/
boolean bDownOver = false; //Downing is over S8+l!$7
boolean bStop = false; //Stop identical ya5HAs
FileAccessI fileAccessI = null; //File Access interface Iz83T9I&
Q`6hJgyL
$tXW/
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException l_$>$d
{ 0I:5}$+J?
this.sURL = sURL; zUDXkG*Lv
this.nStartPos = nStart; Qds:*]vGS
this.nEndPos = nEnd; UZmUYSu;
nThreadID = id; ->o[ S0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 r$-P
} E2t&@t%W
Nn-k hl|11
)4-!]NsV
public void run() `sIm&.d
{ L+T'TC:
while(nStartPos < nEndPos && !bStop) :?LNP3}
{ {Rb;1 eYj
)m+O.`x
zDEgC
try{ .Y^3G7On
URL url = new URL(sURL); KaS*LDzw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); PC+Soh*
httpConnection.setRequestProperty("User-Agent","NetFox"); ?Q+*[YEJ5
String sProperty = "bytes="+nStartPos+"-"; KKb7dZbt<
httpConnection.setRequestProperty("RANGE",sProperty); zY@0R`{@p
Utility.log(sProperty); nk_X_y
GA` bWl
r..f$FF)\
InputStream input = httpConnection.getInputStream(); c`hENPhW
//logResponseHead(httpConnection); #8 ^b]
-sdzA6dp
Gd`7Tf)'
byte[] b = new byte[1024]; YlT&.G
int nRead; 2TQZu3$c
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %X^qWKix}m
{ oR!h eCnu
nStartPos += fileAccessI.write(b,0,nRead); lq]8zm<\)]
//if(nThreadID == 1) rZ5xQ#IA
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \,n X/f
} EE|c@M^
;$1x_ Cb
2A =Y
Utility.log("Thread " + nThreadID + " is over!"); &OE-+z
bDownOver = true; P*>?/I`G
//nPos = fileAccessI.write (b,0,nRead); fVa z'R
} k h*WpX
catch(Exception e){e.printStackTrace ();} +4Wl
} m8x?`Gw~jw
} %K8YZc(&
t6`(9o@}
KF@%tR}V{
//打印回应的头信息 q4Bw5~n
public void logResponseHead(HttpURLConnection con) *?C8,;=2r
{ 6I=xjgwvf
for(int i=1;;i++) . XbDb
{ 8.^`~ta
String header=con.getHeaderFieldKey(i); N?#L{Yt
if(header!=null) Zn40NKYc
//responseHeaders.put(header,httpConnection.getHeaderField(header)); t2.jg?`k
Utility.log(header+" : "+con.getHeaderField(header)); X(17ESQ/Y
else \6.dGKK
break; 7J`v#
} ;;rx)|\<R
} ^&y*=6C
xluAjOQ6
hVT>HER
public void splitterStop() $FIJI^Kd7
{ \L$]2"/v-
bStop = true; fk6=;{
} Pg`+Q^^6S
UM`$aPz
s?;V!t
} '/Vm[L$d
;"e55|d9I
}?Pa(0=U
/* O'^AbO=,
**FileAccess.java P s|[
*//文件访问(定位，写) /NR*<,c%
package NetFox; QhAYCw2
import java.io.*; oa5L5Zr,A
a #s Nd
lA4J#
public class FileAccessI implements Serializable{ K.&6c,P]
6Fk[wH7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 BT;1"l<
RandomAccessFile oSavedFile; EG &me
long nPos; W>?aZv
g2}aEfp!H
v;g,qO!LJ
public FileAccessI() throws IOException qzHsqlof
{ J8@+)hn
this("",0); `:m=rT_
} ){u# (sW
j5[>HL
-Gl!W`$I`
public FileAccessI(String sName,long nPos) throws IOException LV0gw"
{ ;Z;` BGZJ
oSavedFile = new RandomAccessFile(sName,"rw"); cFJZ|Ld
this.nPos = nPos; rW~G'
oSavedFile.seek(nPos); ,If"4C!w
} BVH)!]m0
2\O!vp>|-
=*6frC~
public synchronized int write(byte[] b,int nStart,int nLen) tBwPB#:W
{ DAtAc(05)
int n = -1; wa&:86~l?
try{ -cZuP7oA
oSavedFile.write(b,nStart,nLen); -)bu&
n = nLen; (5y*Btd=
} A]o3MoSt
catch(IOException e) w)YTHY(k;
{ &?y|Pn
e.printStackTrace (); |\"%Dy[m
} i*09m^r
ygQAA!&']
cZrJW
return n; 4IM&#_6
} +, rm
v] Xy^7?
n4"xVDL
} (f#{<^gd
)^)|b5,
;D4 bxz0ou
/* (V/!0Lj
**SiteInfoBean.java I3l1 _
*/ bOV]!)o
package NetFox; Nii5},
Ur""&@
:N xksL^
public class SiteInfoBean { ,>TDxI;
,S, R6#3G
V|nJ%G\
private String sSiteURL; //Site's URL xFp9H'j{
private String sFilePath; //Saved File's Path "68=dC
private String sFileName; //Saved File's Name A/j'{X!z
private int nSplitter; //Count of Splited Downloading File ,p..h+l
^*~4[?]S
*iPBpEWC
public SiteInfoBean() d+8|aS<A
{//nSplitter的缺省值为5 [t5Dd
//default value of nSplitter is 5 L>57eF)7
this("","","",5); g^\>hjNX
} 2Myz[)<P_
i.ivHV~-
!#WJ(zSq
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) X%B2xQM5
{ =A"z.KfV
sSiteURL= sURL; jwwst\f
sFilePath = sPath; eN<?rVZl
sFileName = sName; 4'`*Sce}
this.nSplitter = nSpiltter; |qq29dS?
{UhpN"'"n
%8|?YxiZ:
} Az(J@
/"1[qT\F
OnE~0+
public String getSSiteURL() 2-"`%rE
{ lstnxi%x
return sSiteURL; >LEp EMJ\
} S?~/ V]
7{f{SIB
v(jZ[{x@
public void setSSiteURL(String value) @Z9>E+udQ
{ }iB>3|\
sSiteURL = value; Z2k5qs7g
} ` B+Pl6l)F
Pj*"2 LBW#
-9"[/
public String getSFilePath() (i^<er q
{ k,[[ CZ0j
return sFilePath; FWyfFCK
} n(Ry~Xu_
[>kzQYT[
Yb>A?@S
public void setSFilePath(String value) bLz('mUY
{ v,c:cKj
sFilePath = value; `%0k\,}V
} 8uetv
,aSK L1
sRGIHT#
public String getSFileName() B]cV|S|
{ ]-u>HO g\
return sFileName; ]i'gU(+;`
} I%ZSh]On
M0RVEhX
B+=Xb;p8
public void setSFileName(String value) \YF'qWB
{ fu`|@S
sFileName = value; brt`oR
} "& q])3h=
3#c0p790
t3aDDu
public int getNSplitter() L>2gx$f
{ 4:XVu
return nSplitter; kS(v|d
} aaesgF
C6}`qD
T:EUI]
public void setNSplitter(int nCount) Jd/XEs?<q
{ K;(t@GL?
nSplitter = nCount; JuXuS
} dw< b}2
} !tv+,l&L
* n>YS
|K$EULzz
/* ]Y6y ]u
**Utility.java 'xc=N
*/ o7s<G8;?
package NetFox; UL\gcZ Zkl
Vb8{OD3PK
:.NCS`z_
public class Utility { hc5iIJ]
?N!.:~~k
H-Or
public Utility() @RVj~J.A
{ Pt%EyFG
BYsQu.N
6SmawPPP
} yDBMm^
&GLe4zEh
//线程睡眠 }q[IhjD%
public static void sleep(int nSecond) U10:@Wzh
{ {}v<2bS
try{ }VXZM7@u
Thread.sleep(nSecond); /7XVr"R
} u1i ?L'
catch(Exception e) ++M%PF [ {
{ Z"g6z#L&
e.printStackTrace (); R//S(eU68\
} &dI;o$t
} Y^J/jA0\B
q#!c6lG
//日志 E,:E u<
public static void log(String sMsg) "+KAYsVtU
{ /s~&$(d59o
System.err.println(sMsg); \I`g[nT|
} e't1.%w
RkXW(T`
[^E{Yz=8,
public static void log(int sMsg) `?xE-S ;Pn
{ 5Gsjt+ o
System.err.println(sMsg); [+Y;w`;Fq
} SB2Ij',
} e`D?x1-
/2e,,)4g
dW>$C_`?
/* 92S,W?(
**TestMethod.java -axV;+"b
*/ rA#Ji~
package NetFox; Y!L<& sl
G .k\N(l
[I7([l1Wvd
public class TestMethod { #^&.*'z%z
66shr
0}y-DCuQ
public TestMethod() |F^h>^ x
{ ///xx/weblogic60b2_win.exe _a~-B@2g
try{ Qp]-4%^Vz
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1brKs-z
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /N82h`\n
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0I@Cx{$
fileFetch.start(); ac??lHtH9
} `SSUQ#@
catch(Exception e){e.printStackTrace ();} *Me{G y
GLIP;)h1
sOLR*=F{
} &24z`ZS[w6
v&*}O
%R[X_n=
public static void main(String[] args) 9,zM.g9Qv
{ K+s xO/}h
new TestMethod(); 8cyC\Rs
} 0ge^pO\Z
} d8Kxtg Y
点击下载更多相关资料