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)); Yv/T6z@
} .z, ot|
for(int i=0;i<nEndPos.length-1;i++) IwVdx^9
{ H(gETRh
nEndPos = nStartPos[i+1]; ae>B0#=
} IBz)3gj J
nEndPos[nEndPos.length-1] = nFileLength; =mYwO=:D
} `{1~]?-&
} P47x-;
eXAJ%^iD
Q#5~"C
//启动子线程 ;J,`v5z0:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #SX-Y)> 1@
for(int i=0;i<nStartPos.length;i++) ez14f$cJ+
{ mMw--Gc?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ECk* H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #Dp]S,e
nStartPos,nEndPos,i); K"jS,a?s 6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); P$zhMnAAN
fileSplitterFetch.start(); hf\/2Vl
} d]K$0HY
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), uH |:gF^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;~GBD]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1<;VD0XX
nEndPos = " + nFileLength); slQEAqG)B
// fileSplitterFetch[nPos.length-1].start(); UuCRQNH
-sxu7I
^Rb*mI
//等待子线程结束 >0JCu^9
//int count = 0; ;R]~9Aan
//是否结束while循环 k`BS{,=
boolean breakWhile = false; _t>[gB,
l\WN
^#!\VGnL
while(!bStop) y&(pt!I
{ .Vrl:
write_nPos(); OCELG~
Utility.sleep(500); >BZ,g!N,J}
breakWhile = true; /s@j{*Om
s+E: 7T9P
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for(int i=0;i<nStartPos.length;i++) 5KTPlqm0qF
{ 6[,7g&C
if(!fileSplitterFetch.bDownOver) @77+K:9I7
{ $ZkT G
breakWhile = false; i`w)dS
break; Xc$Zkfmms
} e F)my
} P9)L1l<3I
if(breakWhile) ue*o>iohB
break; H 3so&_
=~TPrO^
?&=JGk^eJ
//count++; "?^#+@LV
//if(count>4) <k 'zz:[c!
// siteStop(); Gkm{b[
} [r1dgwh8
+~"(Wooi
T037|k a{
System.err.println("文件下载结束！"); ioUO0
} P4:Zy;$v!
catch(Exception e){e.printStackTrace ();} 0),fY(D2T
} DWS#q|j`"
YjiMUi\V
_ glB<r$
//获得文件长度 =>XjChM
public long getFileSize() yO` |X
{ >T)tAZ?WK
int nFileLength = -1; @F/,~|{iM
try{ 2({|LQqk
URL url = new URL(siteInfoBean.getSSiteURL()); n~ZZX={a
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <}G/x*N
httpConnection.setRequestProperty("User-Agent","NetFox"); rv c%[HfW;
1DlXsup&?#
=7[}:haB{
int responseCode=httpConnection.getResponseCode(); Zb&"W]HSf
if(responseCode>=400) zt!7aVm n
{ }tL]EW^
processErrorCode(responseCode); kN6jX
return -2; //-2 represent access is error ,H_d#Koa.
} rX0 ?m:&m
R'pfA B|!
M+I9k;N6&
String sHeader; ,/&|:PkS
_WZ{i,
sR^b_/ElxT
for(int i=1;;i++) t'Zv)Wu1E
{ ]Upr<!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); vl~HV8MAv
//Utility.log(in.readLine()); UW1i%u k
sHeader=httpConnection.getHeaderFieldKey(i); 51-'*Y
if(sHeader!=null) }0sLeGJ!
{ 5"ooam3
if(sHeader.equals("Content-Length")) [hV}$0#E[O
{ ]WK~`-3C^
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ZYt1V"2VJ
break; WD1>{TSn
} 1'P4{T0 [
} bokr,I3
else _9dW+
break; z4(`>z2a
} 2O- 4x
} 9I*2xy|I
catch(IOException e){e.printStackTrace ();} Ta$55K0
catch(Exception e){e.printStackTrace ();} uw/N`u
4C )sjk?m
3Kc9*]D
Utility.log(nFileLength); y\,,hs
zK>m4+)~
uzT+,
return nFileLength; d|8-#.gV
} ^"~r/@l
^rd%{6m
FzykC
//保存下载信息（文件指针位置） QNXoAx%I
private void write_nPos() _.E{>IFw
{ AxeQv'e
try{ f^KN8N
output = new DataOutputStream(new FileOutputStream(tmpFile)); X(BX+)YR
output.writeInt(nStartPos.length); M!i*DU+SE
for(int i=0;i<nStartPos.length;i++) *sau['Ha
{ i6$HwRZm#
// output.writeLong(nPos); L2_[M'
output.writeLong(fileSplitterFetch.nStartPos); Q}cti/
output.writeLong(fileSplitterFetch.nEndPos); lEw;X78+
} Yf/e(nV
output.close(); +43~4_Oj
} ^Ku]8/ga
catch(IOException e){e.printStackTrace ();} l`uMtv/Wp
catch(Exception e){e.printStackTrace ();} JLz32 %-M
} $xK\$kw\
n^b CrvD
\RtFF
//读取保存的下载信息（文件指针位置） V(:wYk?ZR
private void read_nPos() >?_}NZ,y
{ y^[t3XA6Q
try{ a5aHv/W#P
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3t9CN )*
int nCount = input.readInt(); A6J:!sY4A
nStartPos = new long[nCount]; -ssmj8:Q\|
nEndPos = new long[nCount]; L8H:,} 2
for(int i=0;i<nStartPos.length;i++) `7'^y
{ 2h#.:!/SMw
nStartPos = input.readLong(); T1R~^x1
nEndPos = input.readLong(); IuA4eDr^Y%
} OnhR`
input.close(); mU
} 3ZI:EZ5
catch(IOException e){e.printStackTrace ();} "shX~zd5
catch(Exception e){e.printStackTrace ();} WnOvU<Z <
} 'Z:wEt!
KFRf5^%
`(gQw~|z
private void processErrorCode(int nErrorCode) ';!-a]N
{ }p-/R'
System.err.println("Error Code : " + nErrorCode); 54B`T/>R:E
} ZJ~0o2xZ'
.z=%3p8+
! 2knSS
//停止文件下载 ~H:=p
public void siteStop() U&=pKbTe
{ 8aC=k@YE
bStop = true; _n!>*A!
for(int i=0;i<nStartPos.length;i++) Kv9FqrDj
fileSplitterFetch.splitterStop(); ~:PM_o*6
oO`a{n-
A:D9qp
} ^FQn\,
} 3aBE[
//负责部分文件的抓取 @'5*jXd
**FileSplitterFetch.java ?m+];SJk
*/ wjZ Q.T!
package NetFox; Gy;Fe=
Ke3~o"IQ
GU9G5S.
import java.io.*; cui%r!D
import java.net.*; 7ku=roPoF
-T i<H9OV
B/qN1D]U.
public class FileSplitterFetch extends Thread { l'M/et{:
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Q'!'+;&%
String sURL; //File URL sDR Av%w
long nStartPos; //File Snippet Start Position YJ-<t6
long nEndPos; //File Snippet End Position + !"YC
int nThreadID; //Thread's ID .C5<uW5-R
boolean bDownOver = false; //Downing is over 7[uN;B#V
boolean bStop = false; //Stop identical 'r ^.Ao5
FileAccessI fileAccessI = null; //File Access interface w{lj'3z I
r%WHYhD
Oo-4WqRJ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException tQYV4h\Qj
{ l_$>$d
this.sURL = sURL; 0I:5}$+J?
this.nStartPos = nStart; m+:JNgX6
this.nEndPos = nEnd; +?ZP3vgGA
nThreadID = id; 63_#*6Pv28
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Ayv:Pv@
} 5''k|B>
cH$(*k9%M
wq,&0P-v
public void run() 7cWeB5e?O
{ [i.c;'Wy/
while(nStartPos < nEndPos && !bStop) e=p_qhBt
{ 6rWq hIaI
R,["w98a
)V+/@4
try{ I<,~>'cq.
URL url = new URL(sURL); {T,}]oX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); K7.ayM 0
httpConnection.setRequestProperty("User-Agent","NetFox"); - US>].
String sProperty = "bytes="+nStartPos+"-"; H3vnc\d~
httpConnection.setRequestProperty("RANGE",sProperty); 2xiE#l-V2
Utility.log(sProperty); B2*>7 kc_s
OwPHp&{ Y
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InputStream input = httpConnection.getInputStream(); wtfH3v
//logResponseHead(httpConnection); *JZ9'|v_H
{dP6fr1z
$)c[FR~a
byte[] b = new byte[1024]; z C$F@
int nRead; t9*e"QH
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (3Xs
{ ]dl.~;3~~
nStartPos += fileAccessI.write(b,0,nRead); "PWGtM:L8Y
//if(nThreadID == 1) -P-8D6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); | oM`
} ZZwIB3sNhf
zBwqIJfM
V@s93kh
Utility.log("Thread " + nThreadID + " is over!"); ,)!%^~v
bDownOver = true; ntB#2S
//nPos = fileAccessI.write (b,0,nRead); ;@Z1y
} lj8ficANo
catch(Exception e){e.printStackTrace ();} S!x;w7j
} ?azLaAG
} RJd*(!y
{06ClI
N?#L{Yt
//打印回应的头信息 Zn40NKYc
public void logResponseHead(HttpURLConnection con) 0bJT0_
{ $bF+J8%D
for(int i=1;;i++) c+7I
{ 7J`v#
String header=con.getHeaderFieldKey(i); bG*l_
if(header!=null) ?/5<}W#7}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); xluAjOQ6
Utility.log(header+" : "+con.getHeaderField(header)); #Tag"b`
else f\=,_AQ
break; fk6=;{
} Pg`+Q^^6S
} yw%ES
L0H^S)g
:SO4@JT{W
public void splitterStop() -:Fr($^
{ }?Pa(0=U
bStop = true; |0>rojMq
} P s|[
}weE^9GiJ
@"98u$5
} qK@,O\
y?3u6q++
EG &me
/* W>?aZv
**FileAccess.java g2}aEfp!H
*//文件访问(定位，写) k\/es1jOEh
package NetFox; t1oTZ
import java.io.*; )@y'$)5s
-`Zk`s|!
jJ@@W~/)B
public class FileAccessI implements Serializable{ N!v>2"x8q
[AD%8H
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #a9R3-aP
RandomAccessFile oSavedFile; \>w 2D
long nPos; <; Td8O89_
?;(!(<{
x2l}$(7
public FileAccessI() throws IOException N>P" $
{ f4dHOH
this("",0); prIJjy-F
} G%i&C)jZ
~"wnlG-:
6"rS?>W/mO
public FileAccessI(String sName,long nPos) throws IOException FcOrA3tt
{ IsFL"Vx
oSavedFile = new RandomAccessFile(sName,"rw"); ww%4MHPp8
this.nPos = nPos; VzcW9'"#
oSavedFile.seek(nPos); /z)8k4
} ,g|ht%"
:,/ \E
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public synchronized int write(byte[] b,int nStart,int nLen) y|9 LtQ
{ G&M)n*o
int n = -1; >%_i#|dE>
try{ ]i `~J
oSavedFile.write(b,nStart,nLen); CJ#Yu3}
n = nLen; mryT%zSlM
} Ur""&@
catch(IOException e) :N xksL^
{ ,>TDxI;
e.printStackTrace (); ,S, R6#3G
} V|nJ%G\
xFp9H'j{
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return n; A/j'{X!z
} ,p..h+l
O7,:-5h0
?DNeL;6
} &,]yqG 2
[t5Dd
L>57eF)7
/* g^\>hjNX
**SiteInfoBean.java 2Myz[)<P_
*/ i.ivHV~-
package NetFox; !#WJ(zSq
lgHzI(
. vea[
public class SiteInfoBean { -#AO4xpI
3[m~6Ys
4'`*Sce}
private String sSiteURL; //Site's URL K5+ONA<c
private String sFilePath; //Saved File's Path 5Ak>/QF9
private String sFileName; //Saved File's Name ]}_Ohe]X
private int nSplitter; //Count of Splited Downloading File gGbqXG^
-N2m|%B
-PiZvge
public SiteInfoBean() ZQ#AEVI,
{//nSplitter的缺省值为5 cW^u4%f't'
//default value of nSplitter is 5 3+D4$Y"
this("","","",5); fEyc3K'5V
} h&bs`
^"$~&\+x5
Psjk 7\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) M;@/697G
{ F;Ubdxwwl
sSiteURL= sURL; 42DB0+_wz
sFilePath = sPath; U }}E E~W
sFileName = sName; ? ~_h3bHH
this.nSplitter = nSpiltter; Vvl8P|x.<
byj7c(
YzAGhAyw
} hB]<li)"C
Ng1[y4R}
X.ZY1vO
public String getSSiteURL() Z3A"GWY
{ -/6Ms%O
return sSiteURL; 5|oi*b
} yrrP#F
Y2y = P
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public void setSSiteURL(String value) M0RVEhX
{ RsP^T:M}$
sSiteURL = value; 95 X6V
} KWT[b?
DGx<Nys@B
"& q])3h=
public String getSFilePath() 3#c0p790
{ t3aDDu
return sFilePath; 'C1yqkIa`
} xO'xZ%cUI
j|(bdTZY:
`[.4SIah
public void setSFilePath(String value) o}lA\A
{ Ns`:=
sFilePath = value; yvKKE
} s!K9-qZl<
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zzyD'n7D
public String getSFileName() !X/O1PM|
{ je~gk6}Y
return sFileName; mF]8
} )m$i``*<
C]%}L%,
o_%gFV[q
public void setSFileName(String value) 'tzN.p1O
{ Q!}LtR$
sFileName = value; hk+"c^g:j<
} ndB*^nT
>U'gQS?\]
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public int getNSplitter() tp=/f !bv
{ WEB enGQ
return nSplitter; u69s}yZ
} *Mr'/qp,
TY*q[AWG
&+F}$8,
public void setNSplitter(int nCount) \"hP*DJ"
{ r#'E;Yx
nSplitter = nCount; Fpf-Fa-K\b
} .ID9Xd$fky
} :jioF{,
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?$rHyI
/* 7e`h,e=
**Utility.java ;CdxKr-d
*/ M/a5o|>8
package NetFox; 3D"?|rd~
Fo[=Dh*AqU
wDS(zG
public class Utility { ( G#W6
|+(Hia,X
^B7C8YP
public Utility() ,*'aH z
{ #`{L_n$c
j+>&~
?;)F_aHp
} :~+m9r
w?zY9Fs=s
//线程睡眠 tR% &.,2
public static void sleep(int nSecond) i$W=5B>SO
{ >4eZ%</D5
try{ R?GF,s<j
Thread.sleep(nSecond); :yC|Q)
} WL/9r *jW
catch(Exception e) "f<+~
{ %oEvp{I
e.printStackTrace (); (dVrGa54
} '2.11cM3
} dX:#KdK
maTZNzy
//日志 TdH~sz
public static void log(String sMsg) 9J'3b <
{ `h|>;u
System.err.println(sMsg); 1$G'Kg/
} X-=J7G`\h#
1(12`3
;Q} H'Wg,
public static void log(int sMsg) 4Gm(P~N
{ d9sqO9Ud8
System.err.println(sMsg); 8cyC\Rs
} =)Q0=!%-
} Fq9>t/Zj
;0`p"T0
@s@67\
/* 5.e. BT
**TestMethod.java [e+$jsPl
*/ Pb-Ft=
package NetFox; v<U +&D{
M~&X?/8
nzK"eNDN.
public class TestMethod { 3?R QPP
*=ymK*
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public TestMethod() uuMHD{}?}
{ ///xx/weblogic60b2_win.exe S0<m><|kl
try{ Vz,2_QJ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !,3U_!
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ^ M4-O~
SiteFileFetch fileFetch = new SiteFileFetch(bean); rv?d3QqIC
fileFetch.start(); ~NtAr1
} $"&U%3
catch(Exception e){e.printStackTrace ();} az2CFd^M
8fwM)DKS
f:-dw6a=s
} Ew kZzVuX
-'OO6mU
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public static void main(String[] args) 5{&<X.jv
{ TGJ\f
new TestMethod(); zUhJr$N$
} Q5s?/r
} 9w! G
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