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)); DZ`,QWuA
} |+~P; fG
for(int i=0;i<nEndPos.length-1;i++) O*2{V]Y @
{ iYa)*,
nEndPos = nStartPos[i+1]; Lcg1X3$G
} F" G+/c/L
nEndPos[nEndPos.length-1] = nFileLength; \7UeV:3Ojn
} 6ImW|%
} }<z[t5
Dd OK&
8\)4waz$
//启动子线程 3Zz_wr6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; dr8Q>(ZY
for(int i=0;i<nStartPos.length;i++) >y}> 5kv
{ 7u1o>a%9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), iyR5mA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), g}?39?o4
nStartPos,nEndPos,i); <%4pvn8d?&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sj+ )
fileSplitterFetch.start(); TJcHqzcUc
} SA"4|#3>7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PTpfa*t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "T8b.ng
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", V[8!ymi0
nEndPos = " + nFileLength); lh\`9F:
// fileSplitterFetch[nPos.length-1].start(); uI)z4Z
+CQIm!Sp
l7WZ" 6d
//等待子线程结束 /w5c:BH
//int count = 0; %}
//是否结束while循环 ](+u'8
boolean breakWhile = false; @Rd`/S@
E)'T;%
u#ocx[
while(!bStop) '*U_!RmQ
{ _0&U'/cs
write_nPos(); rXrIGgeM
Utility.sleep(500); .dc|?$XV
breakWhile = true; 5n::]Q%=D
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j<?k$8H
for(int i=0;i<nStartPos.length;i++) 8`<3rj
{ bHDZ=Ik
if(!fileSplitterFetch.bDownOver) ZSwhI@|
{ ASS<XNP
breakWhile = false; +>tSO!}[
break; ,]@Sytky
} YEiw!
} %~<F7qB
if(breakWhile) .L)j ql%
break; eH;{Ln
4{$ L]toP
}y|_v^
//count++; O/l/$pe
//if(count>4) h?QGJ^#8
// siteStop(); #E/|WT
} 4SkCV
EBmkKiI;
?;rRR48T9E
System.err.println("文件下载结束！"); w~AO;X*Ke"
} JWQd6JQ_~V
catch(Exception e){e.printStackTrace ();} SR4 mbQ:
} j3o?B
-9 |)O:
rB =c
//获得文件长度 pW<l9W
public long getFileSize() EP{ji"/7[
{ q) e*eN
int nFileLength = -1; :dlG:=.W
try{ BE!WCDg,
URL url = new URL(siteInfoBean.getSSiteURL()); H9=8nLb.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7U)w\A;~
httpConnection.setRequestProperty("User-Agent","NetFox"); Qj9'VI>&
SG)|4$"
~. 5[
int responseCode=httpConnection.getResponseCode(); n}J!?zZc
if(responseCode>=400) 4g+o/+6!4
{ ad<ZdO*h
processErrorCode(responseCode); /p{$HkVw
return -2; //-2 represent access is error w\>@>*E>
} o3:h!(#G
}vX1@n7T6
{>yy3(N
String sHeader; .UUT@ w?
2Gc0pBqx
na|23jz4
for(int i=1;;i++) )9{!=k
{ D' h%.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); za5E{<0
//Utility.log(in.readLine()); a;G>56iw
sHeader=httpConnection.getHeaderFieldKey(i); 0fw>/"v
if(sHeader!=null) Zx|VOl,;
{ GS,}]c=
if(sHeader.equals("Content-Length")) 1[(/{CClB
{ l Ztw[c
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _WBWFGj
break; zE=^}K+
} U;]h/3P
} *5" )3\/
else 2()/l9.O'
break; rW2
} ]2mfby
} hhJ>>G4R2
catch(IOException e){e.printStackTrace ();} (7|!%IO.
catch(Exception e){e.printStackTrace ();} V}/AQe2m&
R@[1a+}5
AYoLpes
Utility.log(nFileLength); AgJPtzs
DLEHsbP{$
K1*V\WRW5
return nFileLength; 9t{Iv({6p
} ghaO#kI
tf{o=X.)
<)$JA
//保存下载信息（文件指针位置） 4#D>]AX
private void write_nPos() Z7=k$e
{ !?GW<Rh
try{ LE+#%>z>
output = new DataOutputStream(new FileOutputStream(tmpFile)); 4^K<RSYs
output.writeInt(nStartPos.length); jY$3
for(int i=0;i<nStartPos.length;i++) pLpWc~#
{ :w26d-QR(
// output.writeLong(nPos); 3W@ta1
output.writeLong(fileSplitterFetch.nStartPos); ?_@Mg\Hc
output.writeLong(fileSplitterFetch.nEndPos); QjFE
} CQET
output.close(); 9y*pn|A[F
} cG4$)q;q
catch(IOException e){e.printStackTrace ();} BA`K,#Ft7
catch(Exception e){e.printStackTrace ();} 6z1>(Za7>
} <w0$0ku
'zx1kq1
q=/ck
//读取保存的下载信息（文件指针位置） O.'\GM
private void read_nPos() dQPW9~g8Hg
{ PLQLGb4f_;
try{ 6$\'dkufQ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `>\>'V<&
int nCount = input.readInt(); @HP7$U"
nStartPos = new long[nCount]; $McbVn)~f
nEndPos = new long[nCount]; )uH#+IU
for(int i=0;i<nStartPos.length;i++) Q|nGY:98
{ F44KbUH
nStartPos = input.readLong(); hdy N
nEndPos = input.readLong(); Xs$UpQo
} 0)9'x)l:
input.close(); ]t.6bb4
} cp3O$S
catch(IOException e){e.printStackTrace ();} Aw7_diK^
catch(Exception e){e.printStackTrace ();} Kd').w
} S0p[Kt
/\UFJ
q,2 +\i
private void processErrorCode(int nErrorCode) Q1u/QA:z7
{ >WYradLUi
System.err.println("Error Code : " + nErrorCode); HpR(DG) ?
} ,(Nr_K
s92SN F}g
0tp3mYd
//停止文件下载 +jGSD@32>
public void siteStop() ])$Rw$`w
{ %j2ZQ/z
bStop = true; uxD$dd?
for(int i=0;i<nStartPos.length;i++) Zf8_ko;|:-
fileSplitterFetch.splitterStop(); 6,Y<1b*|Vo
VgcLG ]tE[
l5CFm8%
} x10u?@
} "DU1k6XC
//负责部分文件的抓取 okQ<_1e{
**FileSplitterFetch.java 5!iBKOl#D
*/ a X:,1^
package NetFox; /nVGr]t_pj
h4k.1yH;
I?Ct@yxhF'
import java.io.*; b=Oec%Adx
import java.net.*; I2<5#|CXpZ
>sm<$'vZ/
-)$5[jM]
public class FileSplitterFetch extends Thread { )~H&YINhn
+:#UU;W
nx'Yevi0$
String sURL; //File URL xHi.N*~D
long nStartPos; //File Snippet Start Position m}o4Vr;"
long nEndPos; //File Snippet End Position ;]sbz4?
int nThreadID; //Thread's ID 31k2X81;a
boolean bDownOver = false; //Downing is over Tt\G y
boolean bStop = false; //Stop identical (|.rEaTA[1
FileAccessI fileAccessI = null; //File Access interface [X\~J &kD
O#B2XoZa+
LV!<vakCK
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException HMPb%'U~
{ DNy 6Kw
this.sURL = sURL; vZ/Bzy@|
this.nStartPos = nStart; a?ux
this.nEndPos = nEnd; TjLW<D(i>
nThreadID = id; Vs@H>97,G
fileAccessI = new FileAccessI(sName,nStartPos);//定位 qCku q
} acdF5ch@
Hw 1cc3!
Rr6}$]1
public void run() g]E>e v{`
{ CH+mzy
while(nStartPos < nEndPos && !bStop) u#~q86k
{ K *xca(6
;{f4E)t 7
qttJ*zu
try{ 6PdLJ#LS
URL url = new URL(sURL); xfADks2w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )HJ#|JpxC
httpConnection.setRequestProperty("User-Agent","NetFox"); u5E\wRn
String sProperty = "bytes="+nStartPos+"-"; t @vb3
httpConnection.setRequestProperty("RANGE",sProperty); P&}J(;Lbl
Utility.log(sProperty); `T(T]^C98
?Oyps7hXx
vG'I|OWg
InputStream input = httpConnection.getInputStream(); b&\f 8xZ
//logResponseHead(httpConnection); "DsL$D2e
8q_"aa,`
/7jb&f
byte[] b = new byte[1024]; m%)Cw)t 7
int nRead; wC`+^>WFo
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %+0V0.
{ nX|]JW
nStartPos += fileAccessI.write(b,0,nRead); '4]_~?&x
//if(nThreadID == 1) =dDr:Y<@*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =@y ?Np^A
} >N8*O3
o GN*p_g
m*H' Cb
Utility.log("Thread " + nThreadID + " is over!"); l7vxTj@(-
bDownOver = true; tiQeON-Q_
//nPos = fileAccessI.write (b,0,nRead); ((cRe6
} W}aCU~
catch(Exception e){e.printStackTrace ();} lXOT>$qR<
} qEajT"?
} {dXmSuO
}(/\vTn*1
c4Wl^E8
//打印回应的头信息 ?{rpzrc!*
public void logResponseHead(HttpURLConnection con) cbaa*qoU
{ $i]G'fj
for(int i=1;;i++) AtYqD<hl:
{ .-4]FGg3
String header=con.getHeaderFieldKey(i); bd)'1;p
if(header!=null) i$JN s)I%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); X(JE]6_
Utility.log(header+" : "+con.getHeaderField(header)); <tto8Y j
else N977F$Bo
break; `Y_G*b.Rm
} 8Ai\T_l
} 7-A/2/G<
WO!'("
iph}!3f
public void splitterStop() ?'RB'o~
{ t+Au6/Dx?
bStop = true; |*n B2
} EaKbG>
><i: P*ht
E_-QGE/1
} FW)VyVFmk
_bn "c@s
9>9,
/* ?4cj"i
**FileAccess.java \qz! v
*//文件访问(定位，写) V_/.]zQA
package NetFox; Y1R?,5
import java.io.*; hMnm>
;b_l/T(
/I &wh
public class FileAccessI implements Serializable{ DPr~DO`b
RmRPR<vGW
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "/nbcQ*s*E
RandomAccessFile oSavedFile; %&j\:X~A
long nPos; sf"vii,1A
r1[c+Hy
[,56oMd~
public FileAccessI() throws IOException y;<F|zIm
{ K$I`&M(
this("",0); 7KL@[
} WS//0
-car>hQq
+t%1FkI\
public FileAccessI(String sName,long nPos) throws IOException o[)*Y`xq<w
{ 3?e~J"WXC5
oSavedFile = new RandomAccessFile(sName,"rw"); c8LMvL
this.nPos = nPos; -G(#,rXk
oSavedFile.seek(nPos); n?*r,)'
} spT$}F2n
>R}G
K5!OvqzG
public synchronized int write(byte[] b,int nStart,int nLen) dngG=
{ M $f6.j
int n = -1; !<>*|a
try{ eZBC@y
oSavedFile.write(b,nStart,nLen); h@PE:=
n = nLen; Ot`znJU@
} 2Q5-.2]
catch(IOException e) AQwai>eL
{ |k^C-
e.printStackTrace (); -9Dr;2\
} :!Nx'F9a
V1haAP[#
z(Z7[#.
return n; R@){=8%z
} dhjX[7Bl9
SY.ZEJcv
<nTZs`$LwL
} zx5#eMD
|DYgc$2pN
G=]ox*BY
/* td7Of(k'
**SiteInfoBean.java &0i$Y\g
*/ Fw:_O2
package NetFox; e07u@_'^
>gDeuye
WLA&K]
public class SiteInfoBean { 3CH>!QOA
fN/;BT
(&Rql7](8
private String sSiteURL; //Site's URL 7>=
private String sFilePath; //Saved File's Path 0SQrz$y
private String sFileName; //Saved File's Name pHXs+Ysw+
private int nSplitter; //Count of Splited Downloading File P\WFm
?)T@qn+
@]!9;?so
public SiteInfoBean() 6_:I~TTX
{//nSplitter的缺省值为5 Fv*Et-8tN5
//default value of nSplitter is 5 K|Eelhm
this("","","",5); D5!#c-Y-
} 1_};!5$.
-y>~ :.
<<b]v I
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +#\7 #Y
{ sF>O=F-7
sSiteURL= sURL; 4jSYR#Hqp`
sFilePath = sPath; W*%(J$E
sFileName = sName; zdw* ?C
this.nSplitter = nSpiltter; wX$|(Y}
OADW;fj
Ot)S\s>
} G<* Iw>ep
C1+f\A|9FP
'4_c;](W
public String getSSiteURL() >bd@2au9!
{ ?4oP=.
return sSiteURL; c/igw+L()
} 7377g'jL
8+J>jZ
r6kJV4I=re
public void setSSiteURL(String value) J.'%=q(Sb
{ 8N+T=c
sSiteURL = value; }%z%}V@(&
} ;>L8&m)R5
0ckmHv
bkc*it
public String getSFilePath() hNhEA $X5
{ { 0-on"o
return sFilePath; Ctn 4q'Q
} z:$ibk4#h
)P>/g*
}Z{FPW.QK
public void setSFilePath(String value) !l=)$RJKdD
{ {z\K!=X/
sFilePath = value; lZuH:AH
} rwVp}H G
reNf?7G+m
d^J)Mhju
public String getSFileName() PZ`11#bbm
{ IxS%V31
return sFileName; iPCCTs
} 7~F~'V
xQ7U$QF|]
i/skU9
public void setSFileName(String value) 1.+6x4%rV
{ 3h:y[Vm#9y
sFileName = value; gnjhy1o
} 7F6B
/`7+Gy<
Mn/@?K?y
public int getNSplitter() 'A^q)hpax
{ 92t.@!m`
return nSplitter; ,oh;(|=
} {?5iK1|}K
! xG*W6IT
\Dy|}LE
public void setNSplitter(int nCount) PCHspe9!y
{ )Z:D}r8[
nSplitter = nCount; `:;q4zij;
} /.<v,CR
} Y#XRn_2D
~mARgv
gK9d `5
/* !{(Bc8 hT
**Utility.java ?h&?`WO(
*/ q:TNf\/o
package NetFox; pm,xGo2
8\!E )M|4
BjsT 9?6W/
public class Utility { qSB&Q0T
WA"~6U*
(nt`8 0
public Utility() I](a 5i
{ C[G+SA1&W
|Rz.Pt6
DegbjqZ#
} O"+0 b|
GaG>0x
//线程睡眠 8>,w8(Nt
public static void sleep(int nSecond) `H6~<9r
{ 3>-h- cpMX
try{ #$-E5R;x
Thread.sleep(nSecond); &.\7='$F
} >#x[qX
catch(Exception e) =uH2+9.
{ {V2"Pym?
e.printStackTrace (); *H/3xPh,*
} y'`/^>.
} '2*OrY
a @2fJ}
//日志 [i/!ovcY
public static void log(String sMsg) H{vKk
{ lQHF=Jex
System.err.println(sMsg); X<}}DZSu a
} Ly+UY.v"
_E`+0;O
<3x%-m+p4
public static void log(int sMsg) 32<D9_
{ Qk:Lo*!
System.err.println(sMsg); mGj)Zrx>
} #~|k EGt
} P,{Q k~iu
PY.K_(D
hOUH1m.
/* 'UIFP#GtFO
**TestMethod.java ovTL'j!
*/ \X:e9~
package NetFox; gCb+hQq\
2URGd#{VQ
&Mk!qE<:N
public class TestMethod { ]=qauf>3
_TOWqV^
J8alqs7
public TestMethod() + U5Q/g
{ ///xx/weblogic60b2_win.exe wW@e#:
try{ )N&SrzqTK
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); P3&s<mh
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ORs:S$Nt$
SiteFileFetch fileFetch = new SiteFileFetch(bean); A_zCSRF,
fileFetch.start(); BB/wL_=:
} i D IY|
catch(Exception e){e.printStackTrace ();} I?3b}#&V9
KFd +7C9
'F/oR/4,
} h#hr'3bI1
B>^6tdz
n[iwi
public static void main(String[] args) ^?`fN'!p
{ Swhz\/u9
new TestMethod(); \5r^D|Rp}
} 9:USxFM
} 't5ufAT
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