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)); _Gb O>'kE
} X={Z5Xxr"
for(int i=0;i<nEndPos.length-1;i++) w;=g$Bn
{ kH|cB!?x
nEndPos = nStartPos[i+1]; JQ"R%g`8
} g\~n5=-D
nEndPos[nEndPos.length-1] = nFileLength; 8nKb mjM
} d:&=|kKw
} cy{ ado2
QRFBMq}'
M:/)|fk
//启动子线程 L[rxs[7~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; tH^]`6"QUa
for(int i=0;i<nStartPos.length;i++) i[7<l&K]
{ 2M$^|j:[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n=1_-)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8{)j"rghah
nStartPos,nEndPos,i); l1#F1q`^t
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }T1.~E
fileSplitterFetch.start(); FA7q pc
} U,7O{YM
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4Uzx2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 2, R5mL$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", UVz}"TRq.
nEndPos = " + nFileLength); =+ vl+h
// fileSplitterFetch[nPos.length-1].start(); viXt]0
@Lk!nP
d,+a}eTP'
//等待子线程结束 e4mAKB s!
//int count = 0; /OtLIM+7~{
//是否结束while循环 '5; /V
boolean breakWhile = false; U rL|r.
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while(!bStop) e,8[fp-7
{ 3z~d7J
write_nPos(); 6*r#m%|
Utility.sleep(500); Zog&:]P'F
breakWhile = true; fMluVND
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3D^!U}E
for(int i=0;i<nStartPos.length;i++) mnm7{?#[
{ IDn$w^"
if(!fileSplitterFetch.bDownOver) +JlPQ~5
{ SDHJX8Hq
breakWhile = false; dW#T1mB
break; 5h7M3s
} ,We'AR3X
} -.t/c}a#
if(breakWhile) ]X\p\n'@j
break; 'MK"*W8QRM
?&_u$Nn
sp8P[W1a
//count++; eFXQ~~gOj
//if(count>4) S!6 ? b5
// siteStop(); 9?38/2kX4
} :c}"a(|
u6MHdCJ0y
]9hXiY
System.err.println("文件下载结束！"); .u3Z*+
} peD7X:K\s
catch(Exception e){e.printStackTrace ();} ^SvGSxi
} }O+`X) 9
oa<%R8T?@
M"!{Dx~
//获得文件长度 h,@tfd U^
public long getFileSize() hUP?r/B
{ d3jzGJrU}
int nFileLength = -1; ?, m_q+
try{ 5Ei4$T
URL url = new URL(siteInfoBean.getSSiteURL()); r(OH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'aqlNBG*
httpConnection.setRequestProperty("User-Agent","NetFox"); q#_<J1)z
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7w5C NV
int responseCode=httpConnection.getResponseCode(); opv<r*!
if(responseCode>=400) a?1lj,"~R
{ )uRR!<"~
processErrorCode(responseCode); Ge^(Ag}vE
return -2; //-2 represent access is error %pj T?G7
} 8z)J rO}
dj2w_:&W
}P\J?8
String sHeader; kHz?vVE/l
rk8Cea
Dj9ecV`
for(int i=1;;i++) EV[ BB;eb
{ %v)+]Ds{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {&uN q^Ch
//Utility.log(in.readLine()); apwA
sHeader=httpConnection.getHeaderFieldKey(i); +N2R'Phv
if(sHeader!=null) g+%Pg@[
{ ,Fzuo:{uy
if(sHeader.equals("Content-Length")) vn1*D-?
{ ]=G dAW
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); r,Tq";N'
break; }DFZ9,gQ
} (q}{;
} ,buo&DT{L
else ]6;G#
break; *3#RS
} ZKF #(G
} QP7N#mh
catch(IOException e){e.printStackTrace ();} G]RFGwGt
catch(Exception e){e.printStackTrace ();} -7u_\XFk
yW@YW_2;4
@S)p{T5G
Utility.log(nFileLength); 4|h>.^
8SOfX^;o
Wxzh'c#\8
return nFileLength; v-&@c
} F@<^
"sJ@_lp
3U4h>T@s|
//保存下载信息（文件指针位置） U[G5<&Z^
private void write_nPos() &UIS17cT
{ F5 7Kr5X
try{ 3(3-#MD0
output = new DataOutputStream(new FileOutputStream(tmpFile)); N[&(e d=
output.writeInt(nStartPos.length); |\T!,~
for(int i=0;i<nStartPos.length;i++) v(`5exWV
{ of/' 9Tj
// output.writeLong(nPos); >uR;^B5m
output.writeLong(fileSplitterFetch.nStartPos); eCwR }m?_
output.writeLong(fileSplitterFetch.nEndPos); {)wl`mw3
} ?o`fX wE
output.close(); gr\vC
} RU+F~K<
catch(IOException e){e.printStackTrace ();} Sh(XFUJ
catch(Exception e){e.printStackTrace ();} {nH*Wu*^
} .6A{
suE#'0K
n0b{Jg *
//读取保存的下载信息（文件指针位置） M9QxF
private void read_nPos() 3\j3vcuy
{ '@f#GNRT
try{ 17[vq!x6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :Fdk`aC
int nCount = input.readInt(); d(F4-kBd
nStartPos = new long[nCount]; tUhr gc
nEndPos = new long[nCount]; p!7(ayu
for(int i=0;i<nStartPos.length;i++) S4D~`"4$/
{ 8X)1bNGqhe
nStartPos = input.readLong(); ,lQfsntk'
nEndPos = input.readLong(); cB_3~=fV
} 9 =D13s(C
input.close(); 9d8U@=
} fKNDl\SD
catch(IOException e){e.printStackTrace ();} N >k,"=N/
catch(Exception e){e.printStackTrace ();} J<-2dvq
} T1M>N
B&?xq)%*#
9&Ny;oy#6
private void processErrorCode(int nErrorCode) AME<V-5
{ T;#:Y
System.err.println("Error Code : " + nErrorCode); @T)>akEOt
} YzYj/,?r
/Y8{?
}u.1$Y
//停止文件下载 A?H.EZ
public void siteStop() %:Y'+!bX
{ W<M\b#
bStop = true; qhOV>j,d
for(int i=0;i<nStartPos.length;i++) =po5Q6@i
fileSplitterFetch.splitterStop(); +?+iVLr!l}
9ZG__R3B1\
m`#UV-$J
} "tz`@3,5dN
} w%eEj.MI|i
//负责部分文件的抓取 iJzW3%E
**FileSplitterFetch.java c:,K{ZR
*/ cWp5pGIzfp
package NetFox; dwz{Yw(
Z(hRwIOF
DHh30b$c
import java.io.*; ;k8U5=6a
import java.net.*; X@Yl<9|i
lQ|i Ws
\<x{U3q5
public class FileSplitterFetch extends Thread { {%QWv%|
.2/W.z2
<v$yXA
String sURL; //File URL :2-!bLo}&
long nStartPos; //File Snippet Start Position ,e+S7YX
long nEndPos; //File Snippet End Position ^A$p)`KR
int nThreadID; //Thread's ID J4jL%5t
boolean bDownOver = false; //Downing is over s`o_ER
boolean bStop = false; //Stop identical =:Lc-y>
FileAccessI fileAccessI = null; //File Access interface 6Lz:J:Q)
B^BbA-I
AUPTtc`#Y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Bu#\W
{ Mf`@X[-;
this.sURL = sURL; * NdL4c~
this.nStartPos = nStart; yYvv!w+@Q
this.nEndPos = nEnd; PZhpp"
nThreadID = id; bf$4Z: Y
fileAccessI = new FileAccessI(sName,nStartPos);//定位 fe7DS)U
} zwdi$rM5
9FmX^t$T
qrY]tb^K
public void run() X;3gKiD
{ >?ckBU9
while(nStartPos < nEndPos && !bStop) [-w+ACV~
{ ~%u;lr
*"sDsXo- I
="s>lI-1a
try{ YHI@Cj
URL url = new URL(sURL); pLsJa?}R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @H|3e@5([
httpConnection.setRequestProperty("User-Agent","NetFox"); #<gD@Jybu
String sProperty = "bytes="+nStartPos+"-"; z?Qt%1q
httpConnection.setRequestProperty("RANGE",sProperty); crRYgr
Utility.log(sProperty); v9l|MI15V
+t<'{KZ7;
Hb@PQcj
InputStream input = httpConnection.getInputStream(); ,Cj` 0v#
//logResponseHead(httpConnection); R;F z"J
)r6d3-p1
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byte[] b = new byte[1024]; Rx.dM_S
int nRead; |gM@}!DL
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ]VHO'z\m
{ .{66q#.
nStartPos += fileAccessI.write(b,0,nRead); Ugv"A;l
//if(nThreadID == 1) Lb%:u5X\D@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W3Dtt-)E
} DeGcS1_?
hV[=
_sC kBDl-
Utility.log("Thread " + nThreadID + " is over!"); "oo j;
bDownOver = true; 5)<}a&;{
//nPos = fileAccessI.write (b,0,nRead); {%XDr,myd
} Z)RV6@(
catch(Exception e){e.printStackTrace ();} Ib0@,yS[
} c~{)vL0K
} 992cy2,Fb
WcKL=Z?(
ys Td'J
//打印回应的头信息 ^fT?(y_=e
public void logResponseHead(HttpURLConnection con) *N3X"2X:
{ Xjnv8{X
for(int i=1;;i++) _U`1BmTC2
{ UeN+}`!l
String header=con.getHeaderFieldKey(i); <#No t1R
if(header!=null) GB` G(a
//responseHeaders.put(header,httpConnection.getHeaderField(header)); av4g/7=
Utility.log(header+" : "+con.getHeaderField(header)); ip2BvN&
else {igVuZ(>en
break; Evb %<`gd
} qn#f:xltu
} l]KxUkA+
-`} d@x
Kf'oXCs
public void splitterStop() J?84WS
{ `HJRXoLySW
bStop = true; 9zD^4j7
} a^.5cJ$]
f)%8*B
_Sn7z?
} br_D Orq|
yfCdK-9+B
%Astfn(U{4
/* [+z*&~'
**FileAccess.java Qr$Ay3#k
*//文件访问(定位，写) \KT}T
package NetFox; 9ld'SB:#
import java.io.*; */E5<DO
=U_O;NC
LFT)_DG7(
public class FileAccessI implements Serializable{ .m_-L Y-
|)IS[:X
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 pG(%yIiAi
RandomAccessFile oSavedFile; `w/`qG:dK
long nPos; GV(@(bI*
DSc:>G
p:CpY'KV_
public FileAccessI() throws IOException D+xHTQNTL
{ 3CArUP
this("",0); @"gWvs
} $l<(*,,l
kqyPb$Wy
tv8}O([
public FileAccessI(String sName,long nPos) throws IOException mu# a
{ (_$'e%G0
oSavedFile = new RandomAccessFile(sName,"rw"); ?5MOp
this.nPos = nPos; IW-lC{hK
oSavedFile.seek(nPos); (_'Efpg|
} si.w1
yttIA/
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public synchronized int write(byte[] b,int nStart,int nLen) AQa;D2B$
{ hRKA,u/G
int n = -1; <u%&@G$F>
try{ 5 Yf T
oSavedFile.write(b,nStart,nLen); _"R /k`8
n = nLen; A6#5 z
} 1Xj>kE:
catch(IOException e) *aT\V64
{ )mF;^3
e.printStackTrace (); vS_Ji<W~E
} N56/\1R
\c.MIDp"
"g>, X[g
return n; )T26cT$
} wtpz ef=
jizp\%W+
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} SWrP0Qjc
j`A3N7;
-"Hy%wE
/* ~v+A6N:qC
**SiteInfoBean.java NwPC9!*
*/ p&|:,|jo5
package NetFox; ytg' {)
c mI&R(
uF89B-t
public class SiteInfoBean { 236,o {9e
8%W(",nd
ROc)LCA
private String sSiteURL; //Site's URL z.%K5vrO>
private String sFilePath; //Saved File's Path ^a+H`RD
private String sFileName; //Saved File's Name sj& j\<(
private int nSplitter; //Count of Splited Downloading File C`LHFqv
lZ![?t}2`
c.;}e:)s
public SiteInfoBean() wz{]CQ7"
{//nSplitter的缺省值为5 wW?/`>@
//default value of nSplitter is 5 vjz*B$
this("","","",5); Gl@}b\TB
} OELh6R
~M!s0jT
]= nM|e
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) TCI%Ox|a
{ PH]/*LEj
sSiteURL= sURL; 0M_~@E*&
sFilePath = sPath; 3!:?OUhx
sFileName = sName; EiP#xjn?c
this.nSplitter = nSpiltter; 1FfSqd
:497]c3#5C
pX~X{JTaL)
} M~jV"OF=
S%t*!
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public String getSSiteURL() y6C3u5`
{ O h{>xg
return sSiteURL; ]6BV`r]
} ^;@Q3~DpP%
Y)oF;ko:
^vA"3Ixb!
public void setSSiteURL(String value) $>csm
{ }> pNf
sSiteURL = value; lujUEHzp
} 7j22KQ|EX^
|k ]{WCD]
S(\<@S&
public String getSFilePath() Ga M:/.
{ R@[gkj
return sFilePath; f%2>pQTq@)
} xh) h#p.
}mx>3G{d
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public void setSFilePath(String value) e[ 9
{ 2YV*U_\L
sFilePath = value; oM~;du
} Pv#>j\OR&
(+w>hCI
h.%)RW?
public String getSFileName() ^^FqN;
{ I"5VkeIx
return sFileName; A0f98?j^
} Uxl7O4J@H
A<$w }Fy;
de<T5/
public void setSFileName(String value) ]b6gZ<
{ }S_#*N)i
sFileName = value; zY^QZceq"
} X]T&kdQ6q
s`63 y&Z[
|h6u%t2AY
public int getNSplitter() {)L*\r
{ 8v V<A*`
return nSplitter; 1w#vy1m J
} -qG7,t
ihD|e&
|nY+Nen7
public void setNSplitter(int nCount) \O)u' Bu
{ tR(L>ZG{
nSplitter = nCount; ~*L@|?
} |#EI(W?`
} O@>{%u
Hk?E0.
-^t&U] g
/* T#a6X;9P
**Utility.java uzL|yxt
*/ ~R7{gCqdr
package NetFox; - XB[2h
Kir|in)r0
%:y"o_X_
public class Utility { BJjxy0+
L08"8\
@'"7[k!y;
public Utility() Tx(=4ALY
{ #-/_J?
\3whM6tK
}3R:7N`,|
} Ca0t}`<S
,&jjpeZP
//线程睡眠 >HRLL\u9
public static void sleep(int nSecond) hroRDD
{ 29NP!W /g
try{ JB HnJm
Thread.sleep(nSecond); B|SX?X
} BXr._y, cr
catch(Exception e) Pcr;+'q
{ ]o`FF="at
e.printStackTrace (); vr$z6m ^
} #J%Fi).^)
} dfs1BV'
WiFZY*iu5
//日志 Rr>""
public static void log(String sMsg) )==Qo/N:
{ MsA)Y
System.err.println(sMsg); )`zfDio-1V
} YrTjHIn~w
4<U6jB5
{>l`P{{y
public static void log(int sMsg) 1 w9Aoc
{ cQ/T:E7$`
System.err.println(sMsg); e3kdIOu5
} c1StA
} ;^P0+d^5C
m\ /V0V\
G_?qY#"(
/* hj[sxC>z5
**TestMethod.java q|e<b
*/ r-o6I:y
package NetFox; 9R4q^tGR\
LU@+O12
I^S{V^Ty
public class TestMethod { @fSqGsSk
2LH.If
U KdCG.E9^
public TestMethod() U6oab9C?k
{ ///xx/weblogic60b2_win.exe +K[H!fD
try{ L!kbDbqn
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); LzkwgcR
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); BmFs6{>~c
SiteFileFetch fileFetch = new SiteFileFetch(bean); a5%IjgQ&z
fileFetch.start(); g [+_T{
} sxQMfbN
catch(Exception e){e.printStackTrace ();} Cg&cz]*q|
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XJi^gTN
} <2 S?QgR,
l%$co07cX
B!z5P"C(~
public static void main(String[] args) G7H'OB &
{ d<4q%y'X{
new TestMethod(); yS(tF`H[
} QsH Fk5)
} P[C03a!lXg
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