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)); [k-7Kq
} 8q7KqYu
for(int i=0;i<nEndPos.length-1;i++) <t]c'
{ %H<w.]>
nEndPos = nStartPos[i+1]; _KmpC>J+
} eJ{"\c(
nEndPos[nEndPos.length-1] = nFileLength; K *vNv4
} /Re1QS
} UkNC|#l)
G+[>or}
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//启动子线程 ThWZ>hyJ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?O4Dhu
for(int i=0;i<nStartPos.length;i++) DJ}xD&G
{ ^.kas7<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qa^x4xZM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;~~Oc
nStartPos,nEndPos,i); a,cDj
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7u5B/M!
fileSplitterFetch.start(); 9][Mw[k>
} c}Z,xop<P{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rA*,)I_v@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); AG}' W
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9[T#uh!DC
nEndPos = " + nFileLength); JPQ02&e
// fileSplitterFetch[nPos.length-1].start(); Xki/5roCQ|
8SAz,m!W)
q*{"6"4(
//等待子线程结束 UMhM8m!=o
//int count = 0; w?M*n<) O
//是否结束while循环 +\Q6Onqr
boolean breakWhile = false; .E;6Xx_+r
od^ha
jn}6yXB
while(!bStop) }r^MXv~(
{ gK)B3dH*&
write_nPos(); tY# F8a&
Utility.sleep(500); 5@[%P=
breakWhile = true; A9l^S|r
}f&7<E
)CR8-z1`
for(int i=0;i<nStartPos.length;i++) t1C{
{ 1b|<
if(!fileSplitterFetch.bDownOver) NlcWnSv
{ ,7%(Jj$ ^
breakWhile = false; ;o^m"I\y
break; 1}ZBj%z4l
} /4~RlXf@
} I}:>M!w
if(breakWhile) RB &s$6A
break; ?!~au0
jHz]
gP1$#KgU
//count++; UO:>^,(j
//if(count>4) BM&'3K_y
// siteStop(); Q ;k_q3
} v?LJ_>hw*T
+Z;0"'K'e
+'#d*r91@
System.err.println("文件下载结束！"); 3^ Z tIZ
} tQ&#FFt,)
catch(Exception e){e.printStackTrace ();} IwH ,g^0\
} Jb tbW&EH
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:cC`wX$
//获得文件长度 {Z?!*Ow
public long getFileSize() 7H>dv'
{ R2J3R5S=[
int nFileLength = -1; $(CHwG-
try{ |g;XC^!%=o
URL url = new URL(siteInfoBean.getSSiteURL()); sJM}p5V
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); IBF>4qm"
httpConnection.setRequestProperty("User-Agent","NetFox"); UT{Nly8u
pwZ &2&|
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int responseCode=httpConnection.getResponseCode(); W\KZFrV@
if(responseCode>=400) @ics
{ I" j7
processErrorCode(responseCode); =)I{KT:y
return -2; //-2 represent access is error O/-OW: 03
} @K+u+} R
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*v5y]E%aW
String sHeader; a9qZI
'Gt`3qG
=G72`]#-
for(int i=1;;i++) cxv)LOl-
{ pEaH^(I*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }oU&J81
//Utility.log(in.readLine()); S7SPc
sHeader=httpConnection.getHeaderFieldKey(i); WYzY#-j
if(sHeader!=null) e4`KnHsL
{ QB@*/Le
if(sHeader.equals("Content-Length")) rU~"A
{ GYs4#40
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); jyT(LDsS
break; VI+Y4T@
} ePY K^D
} {MEU|9@ Y
else ,`Mlo
break; 'V>+G>U
} d z\b]H]
} 2'}2r ~6
catch(IOException e){e.printStackTrace ();} =VSieh
catch(Exception e){e.printStackTrace ();} s3knh&'zb
02+^rqIx5
r-0 7!A
Utility.log(nFileLength); 1%:A9%O)t
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return nFileLength; AP~!YwLW
} pKJ[e@E^
\C6m.%%={R
(J;?eeP
//保存下载信息（文件指针位置） 50Jr(OeU<
private void write_nPos() ujSzm=_P
{ Bh.'%[',
try{ 'qD9kJ`
output = new DataOutputStream(new FileOutputStream(tmpFile)); He@= bLLa
output.writeInt(nStartPos.length); *K7L5.
for(int i=0;i<nStartPos.length;i++) (l^lS=x
{ :Oj+Tc9A
// output.writeLong(nPos); <;T7qEIlo
output.writeLong(fileSplitterFetch.nStartPos); @kK=|(OB'
output.writeLong(fileSplitterFetch.nEndPos); s1FBz)yCY=
} D|BN_ai9
output.close(); PDsLJ|:yL
} N1-LM9S
catch(IOException e){e.printStackTrace ();} Ay`a>:p
catch(Exception e){e.printStackTrace ();} <wA_2S Y
} Jzj~uz
bpILiC
N?Z?g_a8
//读取保存的下载信息（文件指针位置） !6%mt}h
private void read_nPos() @rF\6I
{ u`~{:V
try{ pJ(l=a
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `fRy"44nR
int nCount = input.readInt(); FSB$D)4z>b
nStartPos = new long[nCount]; g\Zk*5(
nEndPos = new long[nCount]; aD^MoB3
for(int i=0;i<nStartPos.length;i++) g:)vthOs
{ +Oscy-;
nStartPos = input.readLong(); 1W8W/Y=hT
nEndPos = input.readLong(); O^:h_L
} %qHT!aP
input.close(); =V , _
} b(VU{cf2d
catch(IOException e){e.printStackTrace ();} #(H_w4
catch(Exception e){e.printStackTrace ();} R}VL UL$
} -a[{cu{
>tzXbmFp;
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private void processErrorCode(int nErrorCode) *LVM}| f
{ "10VN*)J}
System.err.println("Error Code : " + nErrorCode); cmeyCyV*
} q ha1b$
{P5@2u6S
m0,9yY::wj
//停止文件下载 .R'i=D`Pz
public void siteStop() i=D,T[|>a
{ ^&.?kJM
bStop = true; -T8 gV1*(<
for(int i=0;i<nStartPos.length;i++) 1sJN^BvuG
fileSplitterFetch.splitterStop(); lN'/Z&62
""d>f4,S
7y\g~?5N
} a*hThr+$M
} 6Ts`5$e
//负责部分文件的抓取 "=(;l3-o
**FileSplitterFetch.java {Jc!T:vJ
*/ /z5lxS@#
package NetFox; #V6 -*
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import java.io.*; *PEuaRDN
import java.net.*; o0L#39`'g
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public class FileSplitterFetch extends Thread { j1<1D@UO
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String sURL; //File URL x,dv~QU
long nStartPos; //File Snippet Start Position q@9i3*q;
long nEndPos; //File Snippet End Position 3Y-v1.^j
int nThreadID; //Thread's ID H~i],WD
boolean bDownOver = false; //Downing is over 81cmG`G7
boolean bStop = false; //Stop identical q1Sm#_7
FileAccessI fileAccessI = null; //File Access interface }D+8K
zf~zYZSr
t] wM_]+
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException to 6Q90(
{ y7OG[L/
this.sURL = sURL; &*aU2{,s,;
this.nStartPos = nStart; @E2nF|N
this.nEndPos = nEnd; ntV>m*^
nThreadID = id; NO^t/(Z
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]LTc)[5Zj
} <h=M Rw,l
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c!Vc_@V,
public void run() J36@Pf]h
{ S(i(1Hs.
while(nStartPos < nEndPos && !bStop) sV[Z|$&Z
{ Xb*_LZAU
hhAC@EGG
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try{ 4d G-
URL url = new URL(sURL); "S`wwl
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vs|6ww
httpConnection.setRequestProperty("User-Agent","NetFox"); #\BI-zt
String sProperty = "bytes="+nStartPos+"-"; o(/ia3
httpConnection.setRequestProperty("RANGE",sProperty); ?w/nZQWi
Utility.log(sProperty); .~L4#V{c~
zI!R-Nb
F |81i$R
InputStream input = httpConnection.getInputStream(); +c`C9RXk
//logResponseHead(httpConnection); v6?\65w,|
m1i+{((
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byte[] b = new byte[1024]; R"gm]SQ/
int nRead; P&0cF{
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) lhl0
{ JK"uj%
nStartPos += fileAccessI.write(b,0,nRead); .oj"ru
//if(nThreadID == 1) 43=-pyp
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?]D+H%3[$i
} y%bqeo L~
Os 2YZ<t
\BaN5+B6
Utility.log("Thread " + nThreadID + " is over!"); BJxmW's/
bDownOver = true; &W+G{W{3
//nPos = fileAccessI.write (b,0,nRead); G!Oq>7
} hX| UE
catch(Exception e){e.printStackTrace ();} 8;\tP29
} jnzz~:
} KH>sCEt
0C+yq'D~[
3dDQz#
//打印回应的头信息 t0H=NUP8
public void logResponseHead(HttpURLConnection con) irb.F>(x
{ h$ iyclX
for(int i=1;;i++) jQeE07g
{ B9)qv>m
String header=con.getHeaderFieldKey(i); p]|ME
if(header!=null) ":#x\;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); w^E]N
Utility.log(header+" : "+con.getHeaderField(header)); GdeR#%z
else 4*XP;`
break; A|_%'8
} [I<'E LX
} MQH8Q$5D
O\F^@;]F6
*Gh8nQbh
public void splitterStop() ajW$d!
{ i^cM@?
bStop = true; i-s?"Fk
} W<N QUf[=
7K]U|K#
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} < Gy!i/
o p5^9`"
^=Tu>{uD
/* h8= MVh(I
**FileAccess.java C+]q
*//文件访问(定位，写) x*"pDI0k)
package NetFox; OjlB0
import java.io.*; K^& ]xFW
k&_u\D"^"%
MN M>
public class FileAccessI implements Serializable{ vua1iN1
CE7pg&dJ)i
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 e9hVX[uq
RandomAccessFile oSavedFile; 6dR-HhF
long nPos; `Y({#U
9c5G6n0
ah"MzU)
public FileAccessI() throws IOException KYmWfM3^
{ M|E2&ht
this("",0); p9 ,\{Is
} bb0McEQy
$s(4?^GP
qTa]th;
public FileAccessI(String sName,long nPos) throws IOException lp0T\ %
{ ))69a
oSavedFile = new RandomAccessFile(sName,"rw"); ])ALAAIc-
this.nPos = nPos; 031.u<_
oSavedFile.seek(nPos); I%Po/+|+
} >-|90CSdSJ
< J<;?%]
0m YZ7S5g
public synchronized int write(byte[] b,int nStart,int nLen) g9weJ6@}M
{ +yP[(b/
int n = -1; ZJI1NCBZ
try{ Up/u|A$0V
oSavedFile.write(b,nStart,nLen); JU=\]E@8c
n = nLen; C(1A8
} >?{iv1
catch(IOException e) XG\a-dq[
{ Vh.;p.!e
e.printStackTrace (); Wh'_slDH+
} ;GgQ@s@
;aK !eD$
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return n; gQpD]p%k
} SL\y\GaV
zr;Y1Xt4
HHIUl,P
} <j1d~XU}
l;{N/cS
NtA|#"^
/* ZG\ I1
**SiteInfoBean.java Z>w^j.(
*/ <E7Vbb9*
package NetFox; j zmSFKg*
\`Ph=lJO
6aF'^6+a
public class SiteInfoBean { qvfAG 0p
(|a$N.e&K
x+*L5$;h
private String sSiteURL; //Site's URL o~.o^0Y
private String sFilePath; //Saved File's Path $YGIN7_Gg
private String sFileName; //Saved File's Name U3|&Jee
private int nSplitter; //Count of Splited Downloading File y%IG:kZ,
@(,{_c]
'^oGDlkr H
public SiteInfoBean() ahi57r[
{//nSplitter的缺省值为5 C@UJOB
//default value of nSplitter is 5 6PQJgki
this("","","",5); z5yb$-j
} =6Kv`
kO,VayjT
wUIsi<Oj
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /VmCN]2AZ
{ H?=pWB
sSiteURL= sURL; '[=yfh
sFilePath = sPath; X4P}aC
sFileName = sName; UU;-q_H6
this.nSplitter = nSpiltter; z7t'6Fy9'
;oY(I7
s7UhC.>'@
} JJ N(M*;
e1 {t0f
B~_,>WG
public String getSSiteURL() cpF1XpvT
{ -|k&L}\OB0
return sSiteURL; CNpe8M=/3
} HV$9b~(
z7@(uIl=X
Ah"'hFY
public void setSSiteURL(String value) 4*D fI
{ Kixr6\
sSiteURL = value; N&x WHFn]C
} m>abK@5na
7{Ki;1B[w
P"V{y|2
public String getSFilePath() ,.6J6{
{ }W__ffH
return sFilePath; J2oWssw"
} 8=n9hLhqo
lZS_n9Sc
+C'TW^
public void setSFilePath(String value) >TlW]st
{ bQ^DX `o6P
sFilePath = value; !0!U01SWa
} /.|A
[yYH>~SuwZ
:Er^"9'A2
public String getSFileName() :!+}XT7)/
{ u^aFj%}]L
return sFileName; >2|[EZ
} ]e@0T{!
!e:iB7<
{;Y 89&*R
public void setSFileName(String value) ==h|+NFa
{ :~ZqB\>i
sFileName = value; eC+"mhB
} QX/X {h6
*%OYAsc
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public int getNSplitter() 't0+:o">:
{ I+Ncmg )>
return nSplitter; Xx3g3P
} w'oo-.k
z_:eM7]jv
bVa+kYE
public void setNSplitter(int nCount) *]}CSZ[>
{ {uaZ<4N.
nSplitter = nCount; 4GU/V\e|
} eq@am(#&kY
} W.#}qK" q
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Hhe{+W@~
/* yyY~ *Le
**Utility.java lC'{QUC
*/ u0bfX,e2U
package NetFox; ?Do^stq'4
c-4m8Kg?L
b!'l\~`{i
public class Utility { N|!MO{sB
biK)&6|`sa
.>mH]/]m
public Utility() ]>R`;"(
{ JmU<y
V;h=8C5J
e/"yGQu
} X q}Ucpj
HE#,(;1i
//线程睡眠 7BL|x
public static void sleep(int nSecond) Q00R<hu@F
{ uipq=Yp.
try{ z-EwXE
Thread.sleep(nSecond); B ~fSMB6h
} csH2_+uG
catch(Exception e) ?muDTD%c
{ di6B!YQP
e.printStackTrace (); Awu$g.
} !dU9sB2
} ]pW86L%
'|vD/Qf=&
//日志 B.89_!/:p
public static void log(String sMsg) A6Ghj{~
{ /y}"M
System.err.println(sMsg); "+=Pp
} L'zE<3O'3
uije#cj#O
,:D=gQ@`
public static void log(int sMsg) a}:A,t<6
{ v8ba~
System.err.println(sMsg); 2 ;JQX!
} Vy-28icZ`
} '3A+"k-}mh
R/^@cA
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/* ' |&>/dyq
**TestMethod.java "-w^D!C
*/ rRB~=J"
package NetFox; \HAJ\9*w)
95=gY
kOw=c Gt
public class TestMethod { J,f/fPaf7
z{ptm7
t)YUPDQ@J
public TestMethod() <fN; xIB
{ ///xx/weblogic60b2_win.exe ev9;Ld
try{ "\e:h| .G
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $}t=RW
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~12_D'8D[
SiteFileFetch fileFetch = new SiteFileFetch(bean); cAD[3b[Gk
fileFetch.start(); N_UQ
} tAF]2VV(e
catch(Exception e){e.printStackTrace ();} \tY"BC4.
i+g~ Uj}h
,V,f2W 4
} =I2@/,
4SgF,ac3r
?w-1:NWjt
public static void main(String[] args) I%oRvg|q
{ eP"`,<
new TestMethod(); XAe\s`
} \V,c]I
} "!O1j r;
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