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)); ;hfG${l;
} |+4E 8;4_
for(int i=0;i<nEndPos.length-1;i++) 31o7R &v
{ [}xIg8
nEndPos = nStartPos[i+1]; 9>$%F;JP44
} |qudJucV
nEndPos[nEndPos.length-1] = nFileLength; w4<u@L
} qdkTg:QJ,
} 6!}m$Dvt~
~_l:b
8L9S^ '
//启动子线程 D^R! |K/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; HNHhMi`w
for(int i=0;i<nStartPos.length;i++) t&Y^W <
{ V@+<,tjq
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dv4r\ R^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), zk^7gx3x
nStartPos,nEndPos,i); ow>[#.ua
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tB(X`A.|
fileSplitterFetch.start(); pQgOT0f
} 4S{l>/I
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hoD[wAC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,9l!fT?iH
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @l6dJ
nEndPos = " + nFileLength); C7*Yg$`{
// fileSplitterFetch[nPos.length-1].start(); 3Ns:O2|
/*R' xBr
u!EulAl
//等待子线程结束 Nno={i1jk
//int count = 0; $GfxMt
//是否结束while循环 B& f~.UH
boolean breakWhile = false; zKAyfn.A
}";hz*a
#.G>SeTn2}
while(!bStop) {D2d({7
{ },QFyT
write_nPos(); iNrmhiql
Utility.sleep(500); BKjPmrZ|
breakWhile = true; ewff(e9
2Z1(J% 7
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for(int i=0;i<nStartPos.length;i++) WZO 0u
{ O [ ;6E
if(!fileSplitterFetch.bDownOver) []fj~hj
{ W!9f'Yn
breakWhile = false; r@V(w`
break; D]>86&
} T6?d`i i1
} 93p9?4;n-
if(breakWhile) RkXLE"G'
break; 'w$we6f
apWrcaj
@Oc}\Rg
//count++; j~j V`>A
//if(count>4) ne~#{q
// siteStop(); GH)+yD[o
} H(ftOd.y
%KVRiX
f*H}eu3/j
System.err.println("文件下载结束！"); |c+N)FB
} P6Z,ci17
catch(Exception e){e.printStackTrace ();} HBkQ`T
} 9mtC"M<
21J82M
g='2~c
//获得文件长度 Y?SJQhN6W
public long getFileSize() K0!#l Br
{ C&K(({5O
int nFileLength = -1; =|t1eSzc
try{ JU`'?b
URL url = new URL(siteInfoBean.getSSiteURL()); XXdMppoR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I Y-5/
httpConnection.setRequestProperty("User-Agent","NetFox"); :95_W/l
V\lF:3C
JG+o~tQC
int responseCode=httpConnection.getResponseCode(); Gqu0M`+7
if(responseCode>=400) oM7-1O
{ o+23?A~+
processErrorCode(responseCode); YO4ppL~xe
return -2; //-2 represent access is error K1:)J.ca_
} w9?wy#YI
"Q!{8 9Y
us *l+Jw,m
String sHeader; K?<Odw'k
ov.rHVeI
^\t">NJ^
for(int i=1;;i++) .3SjkC4I
{ ]V7hl#VO
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *>H'@gS
//Utility.log(in.readLine()); 4>eg@sN
sHeader=httpConnection.getHeaderFieldKey(i); pv.),Iv-68
if(sHeader!=null) \A"a>e
{ 9jFDBy+
if(sHeader.equals("Content-Length")) L.&Vi"M <@
{ Olrw>YbW
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?fwr:aP~
break; t-{OP?cE1
} S^_yiV S
} fO|u(e
else ,(b~L<zN&
break; xGQ:7g+qu
} C 5!6k1TcE
} H zK=UcD
catch(IOException e){e.printStackTrace ();} [-}%B0S**
catch(Exception e){e.printStackTrace ();} e"09b<69
"[Lp-4A\
m/c~2?-;
Utility.log(nFileLength); T>?1+mruM
u"3cSuqy
<t2?Oii;
return nFileLength; D#(Pg
} }=R|iz*,!
vx,6::%]
)CU(~s|s
//保存下载信息（文件指针位置） ov}{UP]a?
private void write_nPos() Xc<9[@
{ Cf 8-%
try{ J8[Xl.
output = new DataOutputStream(new FileOutputStream(tmpFile)); a.Vs>1
output.writeInt(nStartPos.length); ITOGD
for(int i=0;i<nStartPos.length;i++) ?7dDQI7^(
{ l)eaIOyk
// output.writeLong(nPos); 2Nszxvq,
output.writeLong(fileSplitterFetch.nStartPos); )7TTRL
output.writeLong(fileSplitterFetch.nEndPos); xpo}YF'5
} v<4X;4p^
output.close(); jtJU5Q
} uATRZMai
catch(IOException e){e.printStackTrace ();} UzRF'<TWf
catch(Exception e){e.printStackTrace ();} S!c@6&XJm?
} Lg53 Ms%
<0MUn#7'
Kn]WXc|("
//读取保存的下载信息（文件指针位置） :\cJvm
private void read_nPos() lKSI5d
{ \p|!=H@
try{ UY^f|f&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); qTex\qP
int nCount = input.readInt(); mQ)l`wGh
nStartPos = new long[nCount]; MYm6C;o$
nEndPos = new long[nCount]; jP]'gQ!-w
for(int i=0;i<nStartPos.length;i++) ?^0Z(<Arz
{ j|w+=A1
nStartPos = input.readLong(); 27gm_*
nEndPos = input.readLong(); {RO=4ba{J
} &}?e:PEy
input.close(); nhxl#
} YLr2j 7
catch(IOException e){e.printStackTrace ();} ^u<+tV
catch(Exception e){e.printStackTrace ();} XP1_{\
} rJxT)bR
9tgkAU`
"d\8OOU
private void processErrorCode(int nErrorCode) (/BkwbJyE
{ Ke!O^zP92
System.err.println("Error Code : " + nErrorCode); @5ybBh]
} <>GyG-q
p5hP}Z4r
I!bZ-16X
//停止文件下载 y2>]gX5
public void siteStop() 7u(i4O& k
{ &ICO{#v5
bStop = true; lDXH<W?
for(int i=0;i<nStartPos.length;i++) 8hY)r~!b'
fileSplitterFetch.splitterStop(); G 0 yt%qHE
q5Mif\
}9dgm[C[b
} DKH9O
} w[_Uv4M
//负责部分文件的抓取 ^6n]@4P
**FileSplitterFetch.java Sy55w={
*/ :-8u*5QK]`
package NetFox; 7]Yd-vA
iE5^Xik,
`VbG%y&I
import java.io.*; XDQ1gg`
import java.net.*; YKk%;U*
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public class FileSplitterFetch extends Thread { NI)nf;C
%mJ)pMV
}mK_d9dx
String sURL; //File URL 4#uoPkLK
long nStartPos; //File Snippet Start Position o%iTYR:x
long nEndPos; //File Snippet End Position G[ea@u$?
int nThreadID; //Thread's ID /cn_|DwN5
boolean bDownOver = false; //Downing is over k[m-"I%ZFX
boolean bStop = false; //Stop identical |@F<ajlV
FileAccessI fileAccessI = null; //File Access interface o\#e7Hqbh
N3)EG6vE*
.nJGxz+X"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException <Th.}=
{ j7zQ&ANF
this.sURL = sURL; U# gmk0>t{
this.nStartPos = nStart; Zuf&maa S
this.nEndPos = nEnd; dX*PR3I-3
nThreadID = id; !k) ?H* ^@
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~Gza$ K
} *np|PyLP:
'u~use"
:#vrNg(M
public void run() ;8UHPDnst
{ 4!wfh)Z
while(nStartPos < nEndPos && !bStop) Wj0([n
{ (H7q[UG|
t s&C0
Y`v&YcX;
try{ %!RQ:?=
URL url = new URL(sURL); n@f@-d$m\<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); RY&~{yl$"1
httpConnection.setRequestProperty("User-Agent","NetFox"); 5{UGSz 1
String sProperty = "bytes="+nStartPos+"-"; GzX@Av$
httpConnection.setRequestProperty("RANGE",sProperty); S6uBk"V!
Utility.log(sProperty); O #"O.GX<
$oz ZFvJF
3$TpI5A
InputStream input = httpConnection.getInputStream(); L '=3y$"],
//logResponseHead(httpConnection); Wk?XlCj
nBd;d}LD
Cb<\
byte[] b = new byte[1024]; F/h)azcn
int nRead; *!r8HV/<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <v?-$3YT
{ n$>H}#q
nStartPos += fileAccessI.write(b,0,nRead); 3mWN?fC
//if(nThreadID == 1) *hba>LZ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sE% n=Ww
} rHznXME$wZ
/C"E*a
*KNR",.
Utility.log("Thread " + nThreadID + " is over!"); /@K?W=w4
bDownOver = true; G7u7x?E:B`
//nPos = fileAccessI.write (b,0,nRead); 0X;Dr-3<
} xM(
catch(Exception e){e.printStackTrace ();} G8@%)$A
} | =&r) ~
} pdM|dGq^
|"arVde
TA*49Qp
//打印回应的头信息 Z(#a-_g
public void logResponseHead(HttpURLConnection con) D*b> l_
{ xJ4T7 )*
for(int i=1;;i++) iVA_a8}
{ k~R_Pq S
String header=con.getHeaderFieldKey(i); JP#m}W
if(header!=null) -<.>jX
//responseHeaders.put(header,httpConnection.getHeaderField(header)); x~ I cSt
Utility.log(header+" : "+con.getHeaderField(header)); ?AR6+`0
else 4&tY5m>
break; )<+Z,6
} X@B+{IFC
} &}WSfZ0{
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'n\ZmG{
public void splitterStop() l ^{]pD
{ u >x2
bStop = true; R]dc(D
} U7O2.y+
A\:M}D-(
l#Iof)@#
} F$.M2*9
I3$v-OiL
7l?-2I'c
/* `*!.B
**FileAccess.java nRvV+F0#
*//文件访问(定位，写) F4*f_lP
package NetFox; 9K)2OX;$w
import java.io.*; MYu-[Hg
fZgZ
{aU~[5L3(
public class FileAccessI implements Serializable{ FG?B:Zl%T
U]_1yX
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 *0Fn C2W1
RandomAccessFile oSavedFile; FJ/kumq
long nPos; B4|3@X0(
j5AW}
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public FileAccessI() throws IOException B<i1UJ5
{ ?;\YiOTda
this("",0); z`{x1*w_
} =*t)@bn
gq/q]Fm\
iYFM@ta
public FileAccessI(String sName,long nPos) throws IOException VPK)HzPG,
{ ee6Zm+.B
oSavedFile = new RandomAccessFile(sName,"rw"); jQc$>M<"o
this.nPos = nPos; @A g=2\9
oSavedFile.seek(nPos); /|Zk$q.\
} H`kfI"u8
&}6=V+J;
;vuok]@
public synchronized int write(byte[] b,int nStart,int nLen) I6\l6o
{ [(]uin+9Q
int n = -1; 2: fSn&*/>
try{ ;R}:2
oSavedFile.write(b,nStart,nLen); IU&n!5d$)|
n = nLen; (.Sj"6+
} .7{,u1N'
catch(IOException e) R9k Z#
{ l{6fR(d ?
e.printStackTrace (); (tys7og$'
} _K'YaZTa;~
,9=5.+AJ
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return n; g+U6E6}1
} UkeX">
64Q{YuI
rcAx3AK.
} K-#v5_*
iWO16=
5@+4>[tw
/* rqSeh/<iD
**SiteInfoBean.java E<Efxb'p
*/ PU[] Nw
package NetFox; g\GuH?|
[/\}:#MLe
bvi Y.G3
public class SiteInfoBean { A(ql}cr
@}qMI
rMUn ~
private String sSiteURL; //Site's URL y@e/G3
private String sFilePath; //Saved File's Path w_PnEJa9
private String sFileName; //Saved File's Name ^_n(>$ EK
private int nSplitter; //Count of Splited Downloading File B/AS|i] sM
>,7-cm=.
,x&T8o/a
public SiteInfoBean() #,lJ>mTe4
{//nSplitter的缺省值为5 ?`lIsd
//default value of nSplitter is 5 LS <\%A}
this("","","",5); Igrr"NuDZ
} u8 Q`la
G*JasHFs
.7_<0&kW
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) V9bn
{ )T&ZiHIJ3
sSiteURL= sURL; nW1u;.
sFilePath = sPath; tFn_{fCc>
sFileName = sName; 4zzJ5,S1
this.nSplitter = nSpiltter; gLy1*k4
Lk#8G>U
"V'<dn
} QbrR=[8b
+~Wg@
clyZD`*
public String getSSiteURL() _<}oBh
{ n.F^9j+V
return sSiteURL; K+|G9
} lsq\CavbM
L.X"wIs^
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public void setSSiteURL(String value) SI\ O>a9{
{ [&eG>zF"
sSiteURL = value; POB6#x
} J;wDvt]]1
/3#)
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public String getSFilePath() `8M{13fv
{ t.X8c/,;g
return sFilePath; >=O5=\`
} 4fSGc8
mH6\8I
x<d2/[(}mT
public void setSFilePath(String value) C@b-)In
{ W<Ri(g-
sFilePath = value; q[}W&t,
} efN5(9*9R
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public String getSFileName() n~_;tO
{ 6 H{G$[2
return sFileName; gUGMoXSTI|
} f9$8$O
o*_arzhA
<~z@GMQCf
public void setSFileName(String value) 40=*Ul U-
{ Q{=DLm`
sFileName = value; tY@+d*u
} jEMnre3/
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Fa0Fl}L
public int getNSplitter() 1 EL#T&
{ 4LXC;gZ
return nSplitter; T|k_$LH
} {Ri6975
2=IZD `{!
s.$:.*k
public void setNSplitter(int nCount) M.qE$
{ ?+_Y!*J2b
nSplitter = nCount; SDu%rr7sQ
} rczwxWK
} f1AO<>I;
j4%\'xj:
A=96N@m6
/* r;~7$B)
**Utility.java W#9A6ir>
*/ g|Xjw Ti8$
package NetFox; zX8'OoEH*9
`D $ "K1u
Y>2oU`ly,
public class Utility { ^]k=*>{ R
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P" aw--f(
public Utility() ^6@6BYf)
{ ;iA$yw:
n#PXMD*
K |^OnM
} p'4ZcCW?f
T s9go
//线程睡眠 ZFC&&[%-sG
public static void sleep(int nSecond) @rE+H 5
{ @{@DGc
try{ ~Dbu;cqR@
Thread.sleep(nSecond); RPw1i*
} ("s!t?!&YS
catch(Exception e) h'B0rVQia>
{ Pd+Wb3
e.printStackTrace (); g?rK&UTU
} Ri/D>[
} ,l#f6H7p
af_bG;
//日志 QfV:&b`
public static void log(String sMsg) %Vb~}sT:
{ zP>=K
System.err.println(sMsg); nNhb,J
} 1`2lq~=GV
G&q@B`I
:gM_v?sy
public static void log(int sMsg) ts&sr
{ 9w<k1j
System.err.println(sMsg); ~pw%p77)
} ^Sc48iDc
} OzV|z/R2'
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/* 4oPr|OKj{*
**TestMethod.java 6$G@>QCBS
*/ r)gtx!bx
package NetFox; XZ4H(Cj
7&2CLh
B/K{sI
public class TestMethod { @<$_X1)s
E9Hyd #A
\tfhF#'
public TestMethod() 6C- !^8[f
{ ///xx/weblogic60b2_win.exe T#3`&[
try{ `;Xwv)
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); K 5AArI
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Ym wb2]M
SiteFileFetch fileFetch = new SiteFileFetch(bean); "b0!h6$!H
fileFetch.start(); g7r0U6Y
} b`^mpB*6R
catch(Exception e){e.printStackTrace ();} ?Lem|zo
oF.H?lG7`
2f2.;D5g_'
} |#5_VEG
w/wU~~
4EFP*7X
public static void main(String[] args) &!?qSi~V
{ }4_c~)9Q
new TestMethod(); D n}TO*
} GE#LcCa
} :Oc&{z?q
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