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)); !ds"88:5^
} 1VPfa
for(int i=0;i<nEndPos.length-1;i++) t/EMBfLc
{ o)$Q]N##
nEndPos = nStartPos[i+1]; tOp:e KN
} ZKiL-^dob
nEndPos[nEndPos.length-1] = nFileLength; N69eIdl
} "m<eHz]D
} FN8=YUYK%
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PAO[Og,-
//启动子线程 H@OrX
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8=u+BDG
for(int i=0;i<nStartPos.length;i++) Oa3=+_C~$1
{ I*`=[nR
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), a`GN@ 8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), E:LQ!
nStartPos,nEndPos,i); 9|?(GG
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;Fwm1ezx0
fileSplitterFetch.start(); nATfmUN L
} \I`=JKYT
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6>P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); xhp-4
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Sj=69>m]5
nEndPos = " + nFileLength); ,sQ0atk7ma
// fileSplitterFetch[nPos.length-1].start(); 1'@lg*^9
o 0cc+
(,)vak&t
//等待子线程结束 N";dG 3
//int count = 0; e-duZ o
//是否结束while循环 DftGy:Ah3
boolean breakWhile = false; 0wa!pE"
Ot8S'cB1,$
%o_0M^3W
while(!bStop) g)|++?
{ 3 MI) E
write_nPos(); EY[Q%
Utility.sleep(500); Bb2r95h}^
breakWhile = true; aZ`_W|
osgS?=8
odn97,A
for(int i=0;i<nStartPos.length;i++) ^QL/m\zq@%
{ OKLggim{
if(!fileSplitterFetch.bDownOver) j@_) F^12
{ W;)FNP|MT
breakWhile = false; E]U3O>hf
break; +Hm+#o
} #|*,zIYo
} >stVsFdV)
if(breakWhile) $'mB8 S
break; (^s&#_w03
7AFS)_w
DJ2]NA$Q*
//count++; ba)YbP[
//if(count>4) >[P7Zlwv4
// siteStop(); 1p"EE~v
} g,GbaaXH
{J6sM$aj
{-7yZ]OO$
System.err.println("文件下载结束！"); re 1k]
} D A)0Y_
catch(Exception e){e.printStackTrace ();} G]NtX4'4
} +` Y ?-
D``NQ`>A
"VVR#H}{
//获得文件长度 cPBy(5^
public long getFileSize() L)nVpqm
{ ';CuJXAj
int nFileLength = -1; '?>O
try{ Sph"w08
URL url = new URL(siteInfoBean.getSSiteURL()); u$@I/q,ou
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g!)LhE
httpConnection.setRequestProperty("User-Agent","NetFox"); Kac j
V<7K!<g)b
eYSGxcx
int responseCode=httpConnection.getResponseCode(); JW.&uV1Z
if(responseCode>=400) 6UAxl3-\
{ zam0(^=
processErrorCode(responseCode); gl\$jDC9
return -2; //-2 represent access is error E `j5y(44
} /$.vHt5nt
@ un
;gu>;_
String sHeader; _x|8U'|Ce
a4qpnr]0
sluZ-,zE
for(int i=1;;i++) j[ZniD
{ xW;[}t-QS
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); G~hILW^
//Utility.log(in.readLine()); > FcA,
sHeader=httpConnection.getHeaderFieldKey(i); C05{,w?
if(sHeader!=null) cyP*QW[
{ BNoCE!
if(sHeader.equals("Content-Length")) .q[sk
{ pz6- hi7
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =|&"/$+s
break; A_*Lo6uII
} `L[32B9
} h+u|MdOY\
else \V- Y,!~5
break; it|:P
} e^Wv*OD'
} .O-DVW Cm
catch(IOException e){e.printStackTrace ();} 9X&qdA/q
catch(Exception e){e.printStackTrace ();} e`2R{H
-V_S4|>
SR8Kzk{
Utility.log(nFileLength); #2'&=?J1r
N4(VRA
:yFCp@&
return nFileLength; >s?;2T2"yx
} WuZn|j'
_,1kcDu
k<";t
//保存下载信息（文件指针位置） LmdV@gR
private void write_nPos() mb`}sTU).
{ w8#>xV^~
try{ \R6T"U
output = new DataOutputStream(new FileOutputStream(tmpFile)); R M+K":p
output.writeInt(nStartPos.length); 0Lz56e'j
for(int i=0;i<nStartPos.length;i++) Q/`o6xv
{ tYNt>9L|
// output.writeLong(nPos); Wq&c,H
output.writeLong(fileSplitterFetch.nStartPos); m]}"FMH$
output.writeLong(fileSplitterFetch.nEndPos); 19{?w6G<k
} N6 (w<b
output.close(); k)' z<EL6c
} CIvT5^}
catch(IOException e){e.printStackTrace ();} 7Bd_/A($
catch(Exception e){e.printStackTrace ();} kL2sJX+
} nln[V$
HZ4 ^T7G
I[IQFka}
//读取保存的下载信息（文件指针位置） OL"5A18;M
private void read_nPos() <l/Qf[V
{ s/0FSv x
try{ >:nJTr
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); R:m=HS_
int nCount = input.readInt(); QD VA*6F
nStartPos = new long[nCount]; D)cwttH
nEndPos = new long[nCount]; ZGvNEjff
for(int i=0;i<nStartPos.length;i++) V+5 n|L5
{ {#Cm> @')
nStartPos = input.readLong(); c0p=/*s(
nEndPos = input.readLong(); SFNd,(kB*z
} DOU?e9I2
input.close(); 7+r5?h|
} .[85<"C
catch(IOException e){e.printStackTrace ();} k6XmBBIj-
catch(Exception e){e.printStackTrace ();} b:I5poI3
} -7VV5W
1c~#]6[
e1}0f8%
private void processErrorCode(int nErrorCode) iL' ]du<wk
{ leJd){
System.err.println("Error Code : " + nErrorCode); HD|)D5wH|
} 4c@F.I
'E8Qi'g
X_8NW,
//停止文件下载 6x8|v7cMH
public void siteStop() wIHz TL
{ %d\+(:uu/
bStop = true; A8Y~^wn
for(int i=0;i<nStartPos.length;i++) T`[ZNq+${
fileSplitterFetch.splitterStop(); )`7h,w J[1
5R G5uH/-<
^TK)_wx
} :e vc
} (2)9TpE;
//负责部分文件的抓取 ee` =B
**FileSplitterFetch.java Vo8"/]_h
*/ ?+L6o C.;
package NetFox; YWF<2l.
v]S8!wU
bZfJG^3
import java.io.*; %,RU)}
import java.net.*; eA^|B zU
@eU/g![u
!PbFo%)
public class FileSplitterFetch extends Thread { ka[NYW{.
P*sCrGO%
Sd11ZC6
String sURL; //File URL e 3oIoj4o
long nStartPos; //File Snippet Start Position VH65=9z
long nEndPos; //File Snippet End Position KphEw[4/
int nThreadID; //Thread's ID }epN<DL
boolean bDownOver = false; //Downing is over r{&"]'/X
boolean bStop = false; //Stop identical "// 8^e%Xo
FileAccessI fileAccessI = null; //File Access interface j`lK}
Z] }@#/ n
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException o 4wKu
{ .p_$]
this.sURL = sURL; ![jP)WgF
this.nStartPos = nStart; v0H#\p
this.nEndPos = nEnd; -3Hq1
nThreadID = id; Mpx.n]O.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \ziF(xTvqG
} FgaBwd^W
jX@9849@
CB)#; |aDB
public void run() Z^S!w;eu
{ iOxygs#p
while(nStartPos < nEndPos && !bStop) c?S402M}
{ d a9 *>+[
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fsu"Lc
try{ j]^]p;An
URL url = new URL(sURL); p(%x&*)f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?OFvGd
httpConnection.setRequestProperty("User-Agent","NetFox"); <'33!8 G
String sProperty = "bytes="+nStartPos+"-"; $<PVzW,$o
httpConnection.setRequestProperty("RANGE",sProperty); \SR
Utility.log(sProperty); >O=V1
2[eY q1f!
:{2$X|f 3
InputStream input = httpConnection.getInputStream(); x]T;W&s
//logResponseHead(httpConnection); *^ BE1-
yD"sYT
Mk;j"ZDF
byte[] b = new byte[1024]; 0}N^l=jQ
int nRead; Fsh-a7Qp
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) plAt +*&
{ cPSu!u}D
nStartPos += fileAccessI.write(b,0,nRead); EbHeP
//if(nThreadID == 1) 2$=HDwv
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3WS %H17
} C54)eT6
,zaveQ~l
B%/Pn 2
Utility.log("Thread " + nThreadID + " is over!"); \Qn8"I83AV
bDownOver = true; \=~Ap#Mpc4
//nPos = fileAccessI.write (b,0,nRead); huIr*)r&p
} %e(,PL
catch(Exception e){e.printStackTrace ();} 7 &Aakl
} gK'MUZ()
} rOGJ%|%(
3}Pa,uN
Xs/hqIXB
//打印回应的头信息 I(4k{=\ph]
public void logResponseHead(HttpURLConnection con) j?A+qk
{ XijQ)}'C3
for(int i=1;;i++) I(e>ff
{ ';%g^!lM a
String header=con.getHeaderFieldKey(i); WjB[e>
if(header!=null) W%o){+,
//responseHeaders.put(header,httpConnection.getHeaderField(header)); x4K5
Utility.log(header+" : "+con.getHeaderField(header)); FKP^f\!M
else j&9~OXYv
break; NINiX(
} F)G#\r
} &knnWm"
bvG Vfr "
>vhyKq|g<
public void splitterStop() iy 5
{ ZpyRvDz
bStop = true; tznT*EQr
} RfD$@q9
Y~6pJNR
gE&f}M-
} E:ytdaiT
7blZAA?-
='FEC-f95
/* <~3 aaO
**FileAccess.java Cnolka"
*//文件访问(定位，写) cD\Qt9EI
package NetFox; 3^\y>
import java.io.*; Y'P8`$
g6farLBF
\ gN) GR
public class FileAccessI implements Serializable{ c?d#Bj ?
TJ<PT
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 E$T#o{pai
RandomAccessFile oSavedFile; jL# akV
long nPos; *=8)]_=f
+2?[=g4;}
?/\;K1c p
public FileAccessI() throws IOException C"}x=cK
{ =cQwR:):
this("",0); :A$6Y*s\
} ^$(|(N[;
BC+HP9<]
qhtc?A/0}
public FileAccessI(String sName,long nPos) throws IOException )q,}jeM8
{ sM-*[Q=_
oSavedFile = new RandomAccessFile(sName,"rw"); MG6Tk(3S
this.nPos = nPos; \yqiv"'
oSavedFile.seek(nPos); ;Cwn1N9S
} gOkO8P6P8
WXM_H0K
#df43_u
public synchronized int write(byte[] b,int nStart,int nLen) \=@}(<4
{ QqDF_
int n = -1; 8|l Yf%n>j
try{ h\5 7t@A
oSavedFile.write(b,nStart,nLen); \@xnC$dd/
n = nLen; W)l&4#__(
} >iCMjT]4
catch(IOException e) _I9TG.AA.
{ GHkSU;})
e.printStackTrace (); p#&6Ed*V
} 'D4NPG`z
^~0r+w61
.cb mCFXL
return n; Zj JD@,j
} %F7aFvl*
^ey\ c1K
WM#!X!Vo
} AIeYy-f
@.0,ka,X
8c~H![2u
/* @EQ{lGpU3
**SiteInfoBean.java 23>?3-q
*/ B[$e;h*Aw[
package NetFox; g (~&
D"hiEz
ck}y-,>,[O
public class SiteInfoBean { b9U2afd
ql4T@r3l}3
c*h5lM'n6
private String sSiteURL; //Site's URL ,kP{3.#Q
private String sFilePath; //Saved File's Path ^\!^#rO
private String sFileName; //Saved File's Name _k}b
private int nSplitter; //Count of Splited Downloading File ("aYjKk
* n[6H
=:b/z1-v
public SiteInfoBean() #: F)A_Y
{//nSplitter的缺省值为5 3lJK[V{'#'
//default value of nSplitter is 5 A;g[G>J
this("","","",5); pSAXp#g
} >8VJ!Kg4
Ua:EI!`
t!~mbx+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) LKm5U6
{ QK72F
sSiteURL= sURL; A=,m
sFilePath = sPath; YP6+o#==
sFileName = sName; )KNFS,5
this.nSplitter = nSpiltter; R6!3Y/Q@
2@H~nw 0
$OJ*Kul
} o%dtf5}(,
>ko;CQR
."lY>(HJ
public String getSSiteURL() ED6H
{ Q.N^1?(>k
return sSiteURL; WgIVhj
} V=c&QPP
f="}.
;9^B# aTM
public void setSSiteURL(String value) 0e:aeLh
{ 6(z.(eT
sSiteURL = value; ]*@7o^4i
} Kq1sGk
|9g*rO
U3Q'ZT
public String getSFilePath() 4, :D4WYWD
{ 7fVVU+y
return sFilePath; Uq&|iB#mF
} n;MoMGnPh,
a5)+5
2q#$?qs_b
public void setSFilePath(String value) Ft]sTA+C
{ %jkd}D
sFilePath = value; t;*'p
} `R^)<v*
T}zi P
\/5 8#
public String getSFileName() rF5<x3
{ :9)>!+|'
return sFileName; l+#`
} $Fo ,$
iX,Qh2(ig
vEb~QX0~
public void setSFileName(String value) *Vc}W
{ j/W#=\xz
sFileName = value; f(3#5288
} &38Fj'l
lmod8B
3:C *'@
public int getNSplitter() MXhS\vF#m
{ /qz(ra
return nSplitter; M--6oR7
} 3~ qgvAr
'Hq}h)`
gKPV*
public void setNSplitter(int nCount) 4b(iGLrt0
{ H<qR^a
nSplitter = nCount; RpreW7B_Q*
} 8g$ 8]'M^T
} V9MA)If>
<uAqb Wu
T"2ye9a
/* 'r-a:8:t^
**Utility.java kAAz|dhL-
*/ h\yYg'CC
package NetFox; &r_:n t
5ogbse"
;eWVc;H
public class Utility { aB$Y5
2.|Y
*z(.D\{%
public Utility() 3Y=S^*ztd
{ Obw uyhjQ
=]D##R
`T mIrc
} wp@c;gK7
t!K|3>w
//线程睡眠 tV<Au
public static void sleep(int nSecond) t!PFosFp
{ 1e&`m~5K+
try{ h[ tOY
Thread.sleep(nSecond); F<I-^BY)
} 7igrRU#1%
catch(Exception e) {yJ{DU?%Y
{ o`&idn|,
e.printStackTrace (); j6Vuj/+}
} "=qdBG9
} Q@M,:0+cy
`;`34t_)
//日志 Hiq9Jn uv(
public static void log(String sMsg) mxXQBmW
{ pa.W-qyu
System.err.println(sMsg); r^]0LJ
} &^z~wJ,]
G;tIhq[$Vb
Z'u`)jR
public static void log(int sMsg) rMI:zFS
{ GSMP)8W
System.err.println(sMsg); LNr2YRpyz
} 8I@_X~R
} (+9@j(
D,J's(wd
}F^c*xt[
/* aE:fMDS|x
**TestMethod.java &gq\e^0CRZ
*/ 1W;+hXx
package NetFox; Ex~OT
1tD4I
e#08,wgW
public class TestMethod { W/+|dN{O+g
ql],Wplg
!QYqRH~5
public TestMethod() fIFB"toiPE
{ ///xx/weblogic60b2_win.exe Rk"_4zJk
try{ %]NbTTL
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /Cwt4.5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >bmL;)mc&
SiteFileFetch fileFetch = new SiteFileFetch(bean); k8w8I$QEM
fileFetch.start(); Iy"
} y\ouIsI77
catch(Exception e){e.printStackTrace ();} 96 C|R
n#m )]YQC
2p@S-Lp
} >YLwWU<X
d]+g3oy `
cz.-cuD[iD
public static void main(String[] args) {N>VK*
{ {X8F4
new TestMethod(); rU(N@i%
} lQ@2s[
} c~p4M64
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