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)); L+8O 4K{
} nxe9^h7m
for(int i=0;i<nEndPos.length-1;i++) 9s?gI4XN
{ ym'!f|9AA
nEndPos = nStartPos[i+1]; Wjr^: d
} !1Nh`FN
nEndPos[nEndPos.length-1] = nFileLength; r(JP& @
} Cm9#FA
} 0U?(EJ
5RyxVC0<
2Q;rSe._`
//启动子线程 I!T=$Um
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^7YZ>^
for(int i=0;i<nStartPos.length;i++) T9uOOI
{ D/+l$aBz
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <TgVU.*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), g1@rY0O
nStartPos,nEndPos,i); -#,4rN#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); co-1r/ -O
fileSplitterFetch.start(); $Ww.^ym
} M,<UnAVP-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), aI1tG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); FmgMd)#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ZtY?X- 4_
nEndPos = " + nFileLength); AOef1^S=
// fileSplitterFetch[nPos.length-1].start(); ~vcua@
^0?ww&X
v ,zD52
//等待子线程结束 15d'/f
//int count = 0; dtig_s,)D
//是否结束while循环 xXSfYW
boolean breakWhile = false; nX8ulGGs
eo^C[# .
P3v4!tR
while(!bStop) PW\me7iCz
{ ,s/laZ)V
write_nPos(); v>_83P`
Utility.sleep(500); U^]@0vR
breakWhile = true; cUn>gT
J+}z*/)|#
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for(int i=0;i<nStartPos.length;i++) MeV*]*
{ B qLL]%F
if(!fileSplitterFetch.bDownOver) 03"FK"2S
{ dFmpx%+p
breakWhile = false; ay]l\d2!3
break; Y7;=\/SV
} jwSPLq%
} ,.0B0Y-X
if(breakWhile) T[MDjhv'
break; tToP7q^
1\nzfxx
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//count++; s"p\-Z
//if(count>4) z<gII~%
// siteStop(); TeFi[1
} \"w+4}
wj5,_d)
PbFbihg
System.err.println("文件下载结束！"); Q7\j:.
} T8d=@8g,%
catch(Exception e){e.printStackTrace ();} t#w,G
} }zqo<o
JL>DRIR%NV
[I/ZzDMX
//获得文件长度 <C451+95
public long getFileSize() PcjeuJZ
{ 9 9^7Ek!z#
int nFileLength = -1; 1L?d/j
try{ 3#y`6e=5
URL url = new URL(siteInfoBean.getSSiteURL()); [z!pm-Ir
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `G%h=rr^c
httpConnection.setRequestProperty("User-Agent","NetFox"); %evtIU<h
kSEgq<i!
A5Q4wy`
int responseCode=httpConnection.getResponseCode(); x,|fblQz
if(responseCode>=400) { SDnVV
{ C_yNSD
processErrorCode(responseCode); HE>V\+ AL
return -2; //-2 represent access is error |9X2AS Qu
} , K:d/
tH#t8Tq5x
sE ^YOT<
String sHeader; 6cD3(//
^f9@=I
l dp$jrNLr
for(int i=1;;i++) AGKT*l.-
{ F{c8{?:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); M^Tm{`O!
//Utility.log(in.readLine()); ;aD?BD__Z
sHeader=httpConnection.getHeaderFieldKey(i); xxwbX6^d
if(sHeader!=null) FR>[g`1
{ Zr=B8wuT
if(sHeader.equals("Content-Length")) <[u(il
{ W8r"dK
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); vP=H 2P
break; Z4E6J'B8
} (:\L@j
} e)m6xiZ
else pG'?>]Rt4
break; 2EYWX!Bx
} Y*{5'q+2
} c *<m.
catch(IOException e){e.printStackTrace ();} btC6R>0
catch(Exception e){e.printStackTrace ();} +KWO`WR
6/T/A+u
P&<NcOCL&
Utility.log(nFileLength); ^bfU>02Q6p
#{#k;va
e+:X%a4\
return nFileLength; -yb7s2o
} Y88N*axDW.
qq3/K9 #y
.v+W>
//保存下载信息（文件指针位置） s,AJR [
private void write_nPos() xxr'g =
{ IO]tO[P#
try{ f.bwA x
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?$uEN_1O\@
output.writeInt(nStartPos.length); `Q#)N0
for(int i=0;i<nStartPos.length;i++) ~wOMT
{ E9Dy)f]#W
// output.writeLong(nPos); ecO$L<9>
output.writeLong(fileSplitterFetch.nStartPos); hwQ|'^(@O
output.writeLong(fileSplitterFetch.nEndPos); [_(uz,'
} ^f-)gZ&
output.close(); {u9n?Z%
} adRIg:2
catch(IOException e){e.printStackTrace ();} hl] y):
catch(Exception e){e.printStackTrace ();} ,-8Xb+!8I
} /q,=!&f2
7i'clB9!
m1X*I
//读取保存的下载信息（文件指针位置） TTbJ9O<43
private void read_nPos() {P\Ob0)q
{ q/Ji}NGm
try{ bv7xh*/
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )EQI>1_
int nCount = input.readInt(); wZ69W$,p
nStartPos = new long[nCount]; ]YfG`0eK<
nEndPos = new long[nCount]; J><hrZ
for(int i=0;i<nStartPos.length;i++) e'c3.sQ|?
{ o?~27
nStartPos = input.readLong(); m7RyFnR2
nEndPos = input.readLong(); \2#K {
} %cDDu$9;
input.close(); +2}Ar<elP
} -*hPEgcV9
catch(IOException e){e.printStackTrace ();} |9Yx`_DF
catch(Exception e){e.printStackTrace ();} .6y*Z+Zg
} lbw+!{Ch
&5sPw^{,H
dM19;R@4
private void processErrorCode(int nErrorCode) bY*_6SPK4
{ |id7@3leu
System.err.println("Error Code : " + nErrorCode); 6#Y]^%?uy
} <<Y]P+uU
#pPR>,4
E[=&6T4
//停止文件下载 w(X}
public void siteStop() *CAz_s<
{ .y_~mr&d
bStop = true; )"|wWu
for(int i=0;i<nStartPos.length;i++) CdcBE.%<
fileSplitterFetch.splitterStop(); p]?eIovi
zf5%|7o
ZCb@!V}=
} <{hB&4oL
} 20}]b*C}
//负责部分文件的抓取 Zm|il9y4m
**FileSplitterFetch.java mo=@Zt
*/ <7B;_3/
package NetFox; /R?*i@rvf
G&MO(r}B
Z![#Uz.z
import java.io.*; 3-n&&<
import java.net.*; \$t{K
";jAHGbO
a9_2b}t
public class FileSplitterFetch extends Thread { e8egxm
bNtOqhi
PJe\PGh
String sURL; //File URL m7XN6zX
long nStartPos; //File Snippet Start Position %u<r_^w5
long nEndPos; //File Snippet End Position d(9SkXr
int nThreadID; //Thread's ID 'd;aAG
boolean bDownOver = false; //Downing is over )cZ KB0*+
boolean bStop = false; //Stop identical W?.xtQEv
FileAccessI fileAccessI = null; //File Access interface K:Z,4Y
A)d0Z6G`
E5c)\ D
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException <5CQ#^cK
{ e%{7CR'~TD
this.sURL = sURL; @T.F/Pjhc
this.nStartPos = nStart; 8JW0;H<
this.nEndPos = nEnd; J4iu8_eH!D
nThreadID = id; '-G,7!.,r%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \,:7=
} wLt0Fq6QG
99]s/KD2yb
LUz`P6
public void run() y^kC2DS
{ a{%EHL,F
while(nStartPos < nEndPos && !bStop) U~c9PqjZ
{ R iV]SgV9
_+}hId
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try{ /^&$ma\
URL url = new URL(sURL); /jq"r-S"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); irjHPuhcG
httpConnection.setRequestProperty("User-Agent","NetFox"); y] Cx[
String sProperty = "bytes="+nStartPos+"-"; ]#q$i[Y
httpConnection.setRequestProperty("RANGE",sProperty); Aqg$q* Y
Utility.log(sProperty); ?9 `T_,
r.:f.AY{
AP=SCq;
InputStream input = httpConnection.getInputStream(); @e7_&EGR?
//logResponseHead(httpConnection); &qa16bz
ZC^?ng
*S4&V<W>
byte[] b = new byte[1024]; 6+PP(>em
int nRead; dPgA~~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) y6s/S.
{ }:0HM8B7!
nStartPos += fileAccessI.write(b,0,nRead); =umF C[.W
//if(nThreadID == 1) lb"T'}q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S%7bM~J@
} [!ZYtp?Hf
L9whgXD
~IQjQz?
Utility.log("Thread " + nThreadID + " is over!"); {z'Gg
bDownOver = true; YsO`1D
//nPos = fileAccessI.write (b,0,nRead); Rob:W|
} aIWpgUd`
catch(Exception e){e.printStackTrace ();} (ijO|%?
} MUN:}S
} =3,Sjme
nXxnyom,
)%!X,
//打印回应的头信息 yG>sBc
public void logResponseHead(HttpURLConnection con) $ WWi2cI;
{ n4ti{-^4|d
for(int i=1;;i++) sn@)L~$V
{ g|!=@9[dv
String header=con.getHeaderFieldKey(i); icK U)
if(header!=null) ?C6`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \OK}DhY#
Utility.log(header+" : "+con.getHeaderField(header)); lw4#C`bx
else 6b!1j,\Vx
break; Ew9MWlk
} >v%UV:7ap
} ];0:aSi#
EkN>5).
gJzS,g1]
public void splitterStop() i\MW'b
{ m :]F&s
bStop = true; er!+QD,EM
} 7G_lGV_
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.+^o{b
} ]d&;QZ#w
3v<9 Z9O
rO1.8KKJ
/* N=:xyv
**FileAccess.java u)ZZ/|
*//文件访问(定位，写) ['0^gN$:e
package NetFox; 9x9E+DG#(
import java.io.*; 8EI&}I
H329P*P
;[Hrpl S
public class FileAccessI implements Serializable{ R"PO@v
Q@UY4gA'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 q{)Q ?E
RandomAccessFile oSavedFile; %E2C4UbY
long nPos; .>(qZEF
E95VR?nUg
]m^ECA$
public FileAccessI() throws IOException ]JI A\|b6
{ jbTyM"Y
this("",0); cACnBgLl
} OL#RkD
[dXRord
]}AyDy6C
public FileAccessI(String sName,long nPos) throws IOException .O.fD
{ WJ]g7!Ks
oSavedFile = new RandomAccessFile(sName,"rw"); :#W>lq@H
this.nPos = nPos; vYG$>*
oSavedFile.seek(nPos); Aj=c,]2
} R~BW=Dz,e
W{;LI WsZ
d _koF-7
public synchronized int write(byte[] b,int nStart,int nLen) >Q^*h}IdW
{ \Ng[lN
int n = -1; PFeK;`[
try{ O,KlZf_B
oSavedFile.write(b,nStart,nLen); =TXc- J
n = nLen; E}=F
} ~3m} EL
catch(IOException e) 'MIM_m)H
{ ,Onu%
e.printStackTrace (); F?TmOa0
} `#N7ym;s@
HLM"dmI
= G3A}
return n; y|Zj M
} BRMR> ~k(
C/pu]%n@4
^kpu9H
} &]/.=J
<3Hu(Jx<O
&Lgi
/* %|3UWN
**SiteInfoBean.java Ehf{Kl
*/ V?cUQghHg
package NetFox; =p';y&
rhvsd2zi
rk(0w|zR+
public class SiteInfoBean { FKB)o7
>pA9'KWs]
]qc2jut"
private String sSiteURL; //Site's URL b; 4;WtBO
private String sFilePath; //Saved File's Path _qqJ>E<0
private String sFileName; //Saved File's Name \7,'o] >M-
private int nSplitter; //Count of Splited Downloading File ;rH@>VrR
pF"IDC
O8ZHIs
public SiteInfoBean() PK* $
{//nSplitter的缺省值为5 b%,`;hy{
//default value of nSplitter is 5 -f:uNF]Ls
this("","","",5); l=JK+uZ
} Djf,#&j!3
o,RLaS,BK'
lq!l{[Xp
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) yS-owtVCGF
{ `_v|O{DC{
sSiteURL= sURL; ^UK6q2[
sFilePath = sPath; x_5H_! \#
sFileName = sName; ];go?.*C
this.nSplitter = nSpiltter; XX(;,[(_
C zvi':
WChJ <[]W
} D*j\gI
QRv2%^L
r yO\$m
public String getSSiteURL() 6y9#am?
{ ;=6~,k)
return sSiteURL; vH#^|u
} rB:W\5~7
fhmqO0
fm\IQqIK%
public void setSSiteURL(String value) YX_p3
{ R{hKl#j;>
sSiteURL = value; f+huhJS5e
} gI^*O@Q4{b
.gWYKZM
y85/qg)H^
public String getSFilePath() #SRGVa`x
{ ZOG6
return sFilePath; ]f q.r
} j{9sn,<:
xAD:Z"
u#Qd`@p
public void setSFilePath(String value) Ro?aDrQ
{ S:Ne g!`
sFilePath = value; FXOA1VEg
} ``}EbOMG
X] &Q^
;Z"6ve4
public String getSFileName() >LwZ"IEV
{ m$:o+IH/
return sFileName; A@EeX4N
} Jx@3zl
n||/3-HDj
AjK'P<:/
public void setSFileName(String value) 969*mcq'
{ kQ~*iY
sFileName = value; IXugnvyV
} ;z>)&F
(<pc4#B@*
QOkPliX
public int getNSplitter() Dm[4`p@IY\
{ #!KbqRt
return nSplitter; ayuj)]b
} s3W)hU)
*.AokY)_a
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public void setNSplitter(int nCount) aO?(ZL
{ x5k6yHn
nSplitter = nCount; Ex~[Hk4ow
} TDdFuO'}
} E/9 U0
XS]=sfN
ojzO?z
/* b,8W |
**Utility.java AxUj CerNf
*/ ^S'}RZ*>
package NetFox; IDb|J%e^P
&+=A;Y)
vDz)q
public class Utility { TGGeTtk=
pm,&kE
X~GnK>R
public Utility() %lAJ]$m
{ iVzv/Lqm1
Z+@"
@!&\Z[",
} &C<B=T"I
cOthq87:
//线程睡眠 d {a^
public static void sleep(int nSecond) 8'_>A5L/C
{ ~S15tZ $
try{ 9 W><m[O
Thread.sleep(nSecond); 7\'vSHIL
} @;M( oFS9
catch(Exception e) 3Ln~"HwP
{ V= U=
e.printStackTrace (); a;D{P`%n
} ~sshhuF
} Glcl7f"<^
&xMR{:
//日志 ={-\)j
public static void log(String sMsg) 0F6^[osqtl
{ h #Od tc1)
System.err.println(sMsg); y.26:c(
} ?N<* ATCL
6]rIYc[,
k!b\qS~Q
public static void log(int sMsg) Mb=vIk{Bf
{ n;)!N
System.err.println(sMsg); snOd 3Bw
} v-J*PB.0p
} ;(fDR8
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h.ojj$f,
/* *fso6j#%
**TestMethod.java (p'yya{(
*/ |\%[e@u
package NetFox; A9ia[2[
E!&A[TlX\
tbF>"?FY/
public class TestMethod { Nt9M$?\P
ByoSwQ
6uW?xB9
public TestMethod() _?kjIF
{ ///xx/weblogic60b2_win.exe j1%o+#df
try{ 4=td}%
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); b26#0;i
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $Mm=5K%
SiteFileFetch fileFetch = new SiteFileFetch(bean); B>*zQb2:
fileFetch.start(); 4eK!1|1
} trcG^uV
catch(Exception e){e.printStackTrace ();} z$$ E7i
zD:"O4ZM^^
VliX'.-
} z %{Z
5drc8_fZ
DW&%"$2
public static void main(String[] args) .|iMKRq
{ hJ$o+sl
new TestMethod(); `&2~\o/
} B/.+&AJw
} Osncl5PD)
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