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)); ",qU,0
} KW3+luI6
for(int i=0;i<nEndPos.length-1;i++) Li{~=S@N*
{ 2[yBD-":
nEndPos = nStartPos[i+1]; N:5[,O<m_
} }FqA ppr
nEndPos[nEndPos.length-1] = nFileLength; r?$?;%|C
} ))h6~1`
} dFXc/VH')
$7Jo8^RE
}:Z9Vc ZP`
//启动子线程 LRb,VD:/Y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4_?7&G0(
for(int i=0;i<nStartPos.length;i++) qOhO qV
{ {p<Zbm.
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [5d2D,)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), a*dQ _
nStartPos,nEndPos,i); oMH.u^b]fT
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); uZjC c M
fileSplitterFetch.start(); c,\i"=!$
} z_|oCT!6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5z$,6T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); i'/m4 !>h
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?)4?V\$
nEndPos = " + nFileLength); y(jg#7)
// fileSplitterFetch[nPos.length-1].start(); E+95WF|4k"
cQNsL
eDKxn8+(H
//等待子线程结束 [#^#+ |{\
//int count = 0; I27,mS+]
//是否结束while循环 F=a+z/xKT
boolean breakWhile = false; `|Z}2vo;j
kma?v B
<cN~jv-w$
while(!bStop) m:QG}{<.h
{ l,|%7-
write_nPos(); a6xj\w
Utility.sleep(500); sYSLmUZ{
breakWhile = true; RzKb{> ;A
l:B;zi`)oB
1`0#HSO
for(int i=0;i<nStartPos.length;i++) wucV_p.E
{ *Nb#W!
if(!fileSplitterFetch.bDownOver) $^/0<i$
{ <i\A_qqc/
breakWhile = false; C@\{ehG
break; 9=l.T/?sf
} JAc_kl{4O
} C)-^<
if(breakWhile) \*vHB`.,ey
break; >H][.@LyR
m|tC24
DbI!l`Vn4
//count++; ZfAzc6J?\
//if(count>4) 6]cryf&b
// siteStop(); }=](p-]5
} k3!a$0Bs;
. RVVWqW
Njc%_&r
System.err.println("文件下载结束！"); dhPKHrS
} ]$-cMX
catch(Exception e){e.printStackTrace ();} l~:v (R5
} (46 {r}_O
c,EBF\r8*
t:~t@4j}
//获得文件长度 TA18 gq
public long getFileSize() LwqC~N
{ "d/s5sP|S
int nFileLength = -1; '_s}o<
try{ {Bvj"mL]j
URL url = new URL(siteInfoBean.getSSiteURL()); ,Z9>h[JF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &jA\hg#9
httpConnection.setRequestProperty("User-Agent","NetFox"); bp<^R
l(W[_ D
\`.F\Z
int responseCode=httpConnection.getResponseCode(); {16<^
if(responseCode>=400) |iYg >
{ zSTR^sgJ
processErrorCode(responseCode); RSfM]w}Hq#
return -2; //-2 represent access is error Y&bMCI6U
} 6(&Y(/
.\Fss(Zn
<Cpp?DW_
String sHeader; YB))S!;Ok
?WI3/>:<
I_)*)d44_
for(int i=1;;i++) o?Nu:&yE
{ cc=gCE
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }3 m0AQ;K
//Utility.log(in.readLine()); [onqNp
sHeader=httpConnection.getHeaderFieldKey(i); vE, 37
if(sHeader!=null) rnFM/GAy
{ kfb/n)b'
if(sHeader.equals("Content-Length")) U'( sn
{ b8KsR=]4I
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |f( ~@Q:
break; |k 2"_
} CJknJn3m&
} 0BPMmk
else &[R8Q|1j
break; O>y'Nqz
} MhEw _{?
} j`*N,*ha
catch(IOException e){e.printStackTrace ();} 8ovM\9qT
catch(Exception e){e.printStackTrace ();} 4R%*Z~
\YJy#2K
tq50fq'
Utility.log(nFileLength); l;X|=eu'
?8@>6IXn
u0)7i.!M
return nFileLength; p0p4Xh1e
} FyL_xu\e
yoe}$f4
H[Q_hY[>V
//保存下载信息（文件指针位置） kYwb -;
private void write_nPos() ws/63d*
{ EpPf_ \o
try{ ^4Am %yyT
output = new DataOutputStream(new FileOutputStream(tmpFile)); G* b2,9&F
output.writeInt(nStartPos.length); gYAF'?
for(int i=0;i<nStartPos.length;i++) i8X`HbmN
{ Gi6T["
// output.writeLong(nPos); 4-Z()F
output.writeLong(fileSplitterFetch.nStartPos); HjNxqaljt
output.writeLong(fileSplitterFetch.nEndPos); Btt]R
} Yd cK&{
output.close(); er.L7
} |aToUi.Q%
catch(IOException e){e.printStackTrace ();} C_fY %O
catch(Exception e){e.printStackTrace ();} q6P wZ_
} Vn=qV3OE]
KLQTKMNv
2GmpCy`L"
//读取保存的下载信息（文件指针位置） S]3Ev#>
private void read_nPos() R\Z:n*
{ ov#7hxe
try{ qF)<H
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7Du1RuxP
int nCount = input.readInt(); ]<uQ.~
nStartPos = new long[nCount]; V_n<?9^4
nEndPos = new long[nCount]; X26
for(int i=0;i<nStartPos.length;i++) f3*?MXxb16
{ 0o&MB Dp
nStartPos = input.readLong(); 7EhN u@5-
nEndPos = input.readLong(); YA(@5CZ
} +A_J1iJ<
input.close(); H(^bC5'
} $3+PbYY
catch(IOException e){e.printStackTrace ();} n";02?@F
catch(Exception e){e.printStackTrace ();} 36m5bYMd)
} N6oq90G
#1-xw~_
~vdkFc(8B
private void processErrorCode(int nErrorCode) W{cY6@
{ `Kl`VP=c
System.err.println("Error Code : " + nErrorCode); a@d=>CT$
} .4.pJbOg
({}(qm
vdoZ&Tu
//停止文件下载 @MR?6n*k
public void siteStop() !hxIlVd{
{ v{x{=M]
bStop = true; -]G(ms;}/Y
for(int i=0;i<nStartPos.length;i++) s$h] G[x
fileSplitterFetch.splitterStop(); !7B\Xl'S
)o _j]K+xI
+0z 7KO%^^
} d?,M/$h
} 0\{BWNK
//负责部分文件的抓取 D]! aT+
**FileSplitterFetch.java %Tn#-
*/ {.e=qQ%P5)
package NetFox; :q##fG'm/
iP~,n8W
=/Aj
import java.io.*; %T`U^Pnr
import java.net.*; s0UFym8
qd@&59zSh
eKZ%2|+j!7
public class FileSplitterFetch extends Thread { |w}w.%
.]4W!])9
em@EDMvI
String sURL; //File URL /G{_7cb
long nStartPos; //File Snippet Start Position JwnAW}=
long nEndPos; //File Snippet End Position f6<g3Q7Mu
int nThreadID; //Thread's ID }w-wSkl1
boolean bDownOver = false; //Downing is over 4_M>OD/"
boolean bStop = false; //Stop identical /BKe+]dS*
FileAccessI fileAccessI = null; //File Access interface !v#xb3"/
=H7xD"'%R
`rY2up#%
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException )n7l'}o?+
{ }$su4A@0
this.sURL = sURL; OV CR0
this.nStartPos = nStart; 3cl9wWlJ_E
this.nEndPos = nEnd; 1pp -=$k
nThreadID = id; ,0$)yZ3*3,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 R/b4NGW@
} .?C%1a&_l
#>;FUZuJr
]J1S#Q5'
public void run() "T/>d%O1b
{ lw%?z/HDf
while(nStartPos < nEndPos && !bStop) 4NVV5_K a
{ dmrps+L
4NEq$t$Jn
Z*{] ,
try{ 3ucP(Ex@tg
URL url = new URL(sURL); CCijf]+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); JM$.O;y -
httpConnection.setRequestProperty("User-Agent","NetFox"); nHFrG =o,
String sProperty = "bytes="+nStartPos+"-"; R_P}~l
httpConnection.setRequestProperty("RANGE",sProperty); &Jc_Fc(M
Utility.log(sProperty); D.!~dyI.,$
ytEC
H( -Y
InputStream input = httpConnection.getInputStream(); >/f_F6ay#
//logResponseHead(httpConnection); }|)R
2 mjV~
lB8il2&
byte[] b = new byte[1024]; 5,"l0nrk
int nRead; wVs.Vcwr
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %rQuBi# 1f
{ `\>.h
nStartPos += fileAccessI.write(b,0,nRead); Lr;(xw\['
//if(nThreadID == 1) z~6y+
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z1OFcqm
} EfLO5$?rm
k?nQ?B W
< O*6T%;
Utility.log("Thread " + nThreadID + " is over!"); ;d.K_P
bDownOver = true; Q }k.JS~#
//nPos = fileAccessI.write (b,0,nRead); C=Fzu&N}
} eS/B24;*
catch(Exception e){e.printStackTrace ();} tU wRE|_
} 9Vuq,dv
} pC,o2~%{
3{%LS"c
rf+:=|/_3
//打印回应的头信息 RNVbcd
public void logResponseHead(HttpURLConnection con) `D7C?M#j]
{ w^k;D,h
for(int i=1;;i++) }]1BO
{ \h<BDk*
String header=con.getHeaderFieldKey(i); 89}Y5#W
if(header!=null) gE/Tj$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Fh7'[>onw
Utility.log(header+" : "+con.getHeaderField(header)); ?VU(Pq*`
else N<|$h5isq
break; 2g{)AtK$#
} 2],_^XBvB
} p4>$z& _
]Hj<IvG
9ch#}/7B
public void splitterStop() %b.UPS@I
{ q}Z3?W
bStop = true; 8{U-m0v
} FxG7Pk+=
$S*4r&8ZD
Z!xVgM{
} UAF<m1
$$Vt7"F
rtJl _0`
/* tqPx$s
**FileAccess.java q}uHFp/J
*//文件访问(定位，写) $5`!Z%>/
package NetFox; +!-~yf#RE
import java.io.*; h~U02"$
x Ha=3n
U7mozHS,:9
public class FileAccessI implements Serializable{ PHg48Y"Nd
et,GrL)l
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /e\{
RandomAccessFile oSavedFile; z!QDTIb
long nPos; t-u|U(n
=bh*[,-
~H)4)r^
public FileAccessI() throws IOException $v.C0 x
{ 9_ICNG%
this("",0); Thy=yz;p
} $DFv30 f
QlFZO4 P3|
+YOKA*
public FileAccessI(String sName,long nPos) throws IOException qJ!Z~-hS
{ 7z6b@$,
oSavedFile = new RandomAccessFile(sName,"rw"); \ A1uhHP!
this.nPos = nPos; fHrt+_Zn|
oSavedFile.seek(nPos); 6}~pq1IF{
} >e5 *prx+
!U_K&f
- N>MBn
public synchronized int write(byte[] b,int nStart,int nLen) gMWBu~;!
{ .o%^'m"=D[
int n = -1; )o1eWL}
try{ Sydh2d
oSavedFile.write(b,nStart,nLen); ,7Y-k'7Kop
n = nLen; a~h:qpgc
} bo"%0?3n
catch(IOException e) V{-AP=C7
{ n;HHogA
e.printStackTrace (); r,SnXjp@
} 8GPIZh'0h
c;f!!3&
Z!d7&T}
return n; m4K* <
} "\"DCDKmG
Eu}b8c
5/",<1
} 6[qA`x#
pN6%&@) =
x"kjs.d7[<
/* J;t 7&Zpe
**SiteInfoBean.java v1U?&C
*/ )/ Ud^wi
package NetFox; rr`;W}3
d|9b~_::V
{ kSf{>Ia
public class SiteInfoBean { rjt8fN
;?fS(Vz~
.@)mxC:\K9
private String sSiteURL; //Site's URL <mA'X V,
private String sFilePath; //Saved File's Path *F^wtH`
private String sFileName; //Saved File's Name 3gWvmep1
private int nSplitter; //Count of Splited Downloading File +.B<Hd
MfF~8
#$~ba%t9%
public SiteInfoBean() r'LVa6e"N
{//nSplitter的缺省值为5 '[|+aJ
//default value of nSplitter is 5 zr v]
this("","","",5); x}/,yaWZ
} uhH^>z KA
Zd^6ulx
\b V6@#,
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <>xJn{f0c
{ -Lu)'+
sSiteURL= sURL; %m,6}yt
sFilePath = sPath; ha@L94Lq
sFileName = sName; @tohNO>
this.nSplitter = nSpiltter; "|Fy+'5}
0Q,g7K<d
Kemw^48ts
} GY3Wj
;rI@*An
nZ1zJpBmI
public String getSSiteURL() 5la>a}+!!h
{ .JX EK
return sSiteURL; >%p{38
} VLsxdwHgb
C,V%B
1sE?YJP-
public void setSSiteURL(String value) 8*SDiZ
{ qs\2Z@;
sSiteURL = value; )C(>H93
} NqHy%'R
{_N,=DQ!
vE6mOM!_L
public String getSFilePath() ~0$NJrUy
{ -\ZcOXpMx=
return sFilePath; 5*PYT=p}
} `0H g y=
c$S{^IQ
cEW0;\$
public void setSFilePath(String value) 2M<R(W!&
{ I4;A8I
sFilePath = value; m p<1yY]
} <99M@ cF
]Y6cwZOe
-m'j]1
public String getSFileName() i"zuil
{ N#V.1<Y
return sFileName; m^'uipa\
} lN,/3\B
H|ozDA
rrg96WD
public void setSFileName(String value) $p!yhn7
{ }7fZ[J3
sFileName = value; '[$)bPMHl
} 7*j (*
eD$M<Eu
"gd=J_Yw
public int getNSplitter() ^Jb H?
{ HS'Vi9
return nSplitter; Er/bO
} Ze<K=Q%(i
UT~a&u
tqAd$:L
public void setNSplitter(int nCount) @3fn)YQ'
{ NC&DFJo
nSplitter = nCount; A,i75kd
} iu**`WjI\
} qQ\Y/}F
%6Q4yk
3X9b2RY*L/
/* b[z]CP
**Utility.java jVLA CWH
*/ 2._X|~0a
package NetFox; JvYPC
!8 &=y
T5urZq*R
public class Utility { +% /s*EC'w
0CSv10Tg
Iff9'TE
public Utility() '65LKD
{ ~HQ9i%exg
ntNI]~z&
R1&unm0
} \xg]oKbn
k6`6Mjbc
//线程睡眠 L lqM c
public static void sleep(int nSecond) (F7(^.MG
{ G!4(BGx&
try{ zf3v5Hk
Thread.sleep(nSecond); yH][(o=2
} AM=z`0so
catch(Exception e) J0zn-
{ +C7 ~b~ %
e.printStackTrace (); zMIT}$L
} Zmbfq8K
} {M,,npl
^Rm
//日志 S9HwIH\m
public static void log(String sMsg) .^J2.>.
{ MX>[^}n
System.err.println(sMsg); `1:{0p2q
} *<1r3!
@aJ!PV'ms
EpQ8a[<-3
public static void log(int sMsg) `3p~m,
{ c8Z wr]DF
System.err.println(sMsg); vb9OonE2
} E2)h?cs
} x8GJY~:SW
-OSa>-bzNx
2Sm}On
/* ;#w3{ NB
**TestMethod.java 0M\D[mg
*/ j,]Y$B
package NetFox; RK w$-7O
UGK*Gy
%`Z!4L
public class TestMethod { NnVnUgx
(sWLhUgRX
G[jW<'f
public TestMethod() iQ{G(^sZN
{ ///xx/weblogic60b2_win.exe \"hJCP?,
try{ A!^q J#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); qZ@s#UiB
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); w3jO6*_ M
SiteFileFetch fileFetch = new SiteFileFetch(bean); vq34/c^
fileFetch.start(); =B.F;40
} j65<8svl
catch(Exception e){e.printStackTrace ();} I%urz!CNE*
U*.0XNKp{
}-~l!
} J90v!p-
YJ$1N!rG
m,fAeln
public static void main(String[] args) -*.-9B~u
{ :6$>_m=i
new TestMethod(); Sp@-p9#
} V59(Z
} kQ]$%Lk[
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