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)); =bn(9Gm!J
} 5AX AIPn)
for(int i=0;i<nEndPos.length-1;i++) _G$SA-W(
{ G~$.Af!9W
nEndPos = nStartPos[i+1]; HC%tJ:G
} D'{NEk@
nEndPos[nEndPos.length-1] = nFileLength; Z%h _g-C
} B=EI&+F+
} <F>^ffwGH-
&sFEe<
4*j6~
//启动子线程 O)0}yF$0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }6Ut7J]a|
for(int i=0;i<nStartPos.length;i++) <)hA?3J
{ bOEO2v'cQ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W^a-K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), cRR[ci34k
nStartPos,nEndPos,i); H@+1I?l
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `"7}'|
fileSplitterFetch.start(); 3q$[r_
} M2pe*z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), aw%iO|M_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); GnX+.uQL|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^{Vt
nEndPos = " + nFileLength); :,@"I$>*/
// fileSplitterFetch[nPos.length-1].start(); jOkc'
QR ?JN\%?
t2L}
//等待子线程结束 QLs9W&PG
//int count = 0; 6KvoHo
//是否结束while循环 j_(DH2D
boolean breakWhile = false; KF4D)NM|
t!=qt*
%9q]
while(!bStop) Mr0<b?I
{ 4# L}&
write_nPos(); |w{}h6a
Utility.sleep(500); Bf21u9
breakWhile = true; >3C4S
;u(#-C2^{l
c\Z.V*o
for(int i=0;i<nStartPos.length;i++) vvTQ!Aa
{ |Ix{JP"Lk
if(!fileSplitterFetch.bDownOver) '%H\k5^
{ g3Xab
breakWhile = false; 3)6TnY/u6{
break; 9a6ij*#
} D2y[?RG
} 18HmS>Qo
if(breakWhile) xg^Z. q)d
break; *=2sXH1j
f?qp*
~pC\"LU`
//count++; tl=H9w&@
//if(count>4) 9cnLf#
// siteStop(); @Y&UP
} joRrsxFU
^.pd'
Hrg~<-.La
System.err.println("文件下载结束！"); *U mWcFoF
} xXRlQ|84
catch(Exception e){e.printStackTrace ();} -cONC9=
} mm:g9j
8#{DBWU
+V`*
//获得文件长度 ?'IY0^
public long getFileSize() !qe:M]C'l
{ k9_c<TSzu
int nFileLength = -1; h@{mcz
try{ _/5#A+ ?
URL url = new URL(siteInfoBean.getSSiteURL()); I^l\<1"]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1PUeU+
httpConnection.setRequestProperty("User-Agent","NetFox"); UOa n
!de`K |
MJM<
int responseCode=httpConnection.getResponseCode(); m#,AD,s
if(responseCode>=400) VsQ~Y,7
{ i}gsxq%
processErrorCode(responseCode); (Zoopkxw
return -2; //-2 represent access is error l<)k`lrMX4
} J|aU}Z8m
L}\ oFjVju
GWa:C\YK
String sHeader; He)!Ez\X
$1uT`>%
~zYk,;m
for(int i=1;;i++) +GvPJI
{ 61W[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6qd?&.=r
//Utility.log(in.readLine()); uZml.#@4
sHeader=httpConnection.getHeaderFieldKey(i); \RS ,Y
if(sHeader!=null) y#{v\h Cz
{ gVI{eoJ
if(sHeader.equals("Content-Length")) s3[\&zt
{ eL_Il.:
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |" ag'h
break; Bp-e< :
} dT7!+)s5-
} ;R([w4[~
else -oT3`d3
break; 2C AR2V|
} .$ X|96~$
} FEA t6
catch(IOException e){e.printStackTrace ();} }u]7x:lh
catch(Exception e){e.printStackTrace ();} lSG]{
a];1)zVA6
Ku?1QDhrF*
Utility.log(nFileLength); ;~GBD]
1<;VD0XX
QTospHf`
return nFileLength; !LJ4 S
} 4x-K0
yVe<+Z\7
r1BL?&X-
//保存下载信息（文件指针位置） ;R]~9Aan
private void write_nPos() k`BS{,=
{ _t>[gB,
try{ d*_rJE}B
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^#!\VGnL
output.writeInt(nStartPos.length); joBS{]
for(int i=0;i<nStartPos.length;i++) E1s~ +
{ vP%}XEF
// output.writeLong(nPos); 'Pe;Tp>`
output.writeLong(fileSplitterFetch.nStartPos); no(or5UJ
output.writeLong(fileSplitterFetch.nEndPos); @~bP|a
} :3[;9xCHj
output.close(); }=d}q *
} k\X yR4r
catch(IOException e){e.printStackTrace ();} 8RT<?I^5
catch(Exception e){e.printStackTrace ();} Gdz*
} [P`<y#J3F
zvn3i5z
l:~/%=
//读取保存的下载信息（文件指针位置） P~;1adi3
private void read_nPos() "hnvND4=
{ ~;}uYJ
try{ 8?1MnjhX10
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); I2WWhsNC
int nCount = input.readInt(); 1<Vke$
nStartPos = new long[nCount]; $IqubC>O
nEndPos = new long[nCount]; :{9HsF"h0
for(int i=0;i<nStartPos.length;i++) ]Pe8G(E!
{ )jjL'
nStartPos = input.readLong(); yN/g;bQ
nEndPos = input.readLong(); 1&RB=7.h
} Vqr]Ui
input.close(); P4:Zy;$v!
} 0),fY(D2T
catch(IOException e){e.printStackTrace ();} Fl!D2jnN
catch(Exception e){e.printStackTrace ();} &88c@Ksn
} |G/U%?`
C]&/k_k
3Ww 37V>h
private void processErrorCode(int nErrorCode) -<:w{cV
{ iB5q"hoZC
System.err.println("Error Code : " + nErrorCode); KQ^|prN?y
} .hJcK/m
urg^>n4V]
(Q=:ln;kM
//停止文件下载 aeDhC#h
public void siteStop() .{-X1tJ7
{ Zb&"W]HSf
bStop = true; zt!7aVm n
for(int i=0;i<nStartPos.length;i++) }tL]EW^
fileSplitterFetch.splitterStop(); V -_MwII-
$o/i / wcj
[?bq4u`
} U6.hH%\}@
} MDBqIL]Hc
//负责部分文件的抓取 @Z5,j)
**FileSplitterFetch.java AH?[K,3
*/ h.wffk,
package NetFox; 5uV_Pkb?8
gvr&7=p
!>f:wk2
import java.io.*; ~14|y|\/
import java.net.*; <"8F=3:uk
4"UH~A;^
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public class FileSplitterFetch extends Thread { cl`7|;v|?
y t7>,
{<1uV']x
String sURL; //File URL 4 !m'9
long nStartPos; //File Snippet Start Position 4I9Yr
long nEndPos; //File Snippet End Position $y{.fjy3
int nThreadID; //Thread's ID ;p7R~17
boolean bDownOver = false; //Downing is over S$gLL kD1
boolean bStop = false; //Stop identical =!)x`1j!S
FileAccessI fileAccessI = null; //File Access interface ?dXAHY
BF 0#G2`h>
`KZu/r-M9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException UCj:]!P
{ _GM?`
this.sURL = sURL; > H&v
this.nStartPos = nStart; ^CgN>-xZ?#
this.nEndPos = nEnd; MS:,I?
nThreadID = id; wp83E,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Bw~jqDZ}|
} 6uTC2ka[&R
%`~+^{Wp
rGrR;
public void run() G9Noch9 g
{ fhyoSRLR:
while(nStartPos < nEndPos && !bStop) j7$xHnV4
{ QNXoAx%I
_.E{>IFw
9GsG*$-I
try{ f^KN8N
URL url = new URL(sURL); )~gIJW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +d?|R5{3
httpConnection.setRequestProperty("User-Agent","NetFox"); KyQTrl.qdl
String sProperty = "bytes="+nStartPos+"-"; +Jm vB6s
httpConnection.setRequestProperty("RANGE",sProperty); JTObyAoW
Utility.log(sProperty); ex^9 l b
e1y#p3 @d
(BngwLVDK
InputStream input = httpConnection.getInputStream(); N|%r5%
//logResponseHead(httpConnection); =k,?+h~
X,Rl&K\b"
,N;2"$+E
byte[] b = new byte[1024]; dkY JO!
int nRead; =M}tet }
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) It<VjN9
{ [#YzU^^Ib
nStartPos += fileAccessI.write(b,0,nRead); e"*1l>g
//if(nThreadID == 1) $:# :"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4GH&u,
} +XSe;xk;rD
A@Lr(L
?!<Q8=
Utility.log("Thread " + nThreadID + " is over!"); 7yXJ\(6R_
bDownOver = true; F'F6 &a+
//nPos = fileAccessI.write (b,0,nRead); 5;G0$M0
} J{\(Y#|rHs
catch(Exception e){e.printStackTrace ();} &['L7
} Bp@\p)P(
} j9yOkaVEg
|i~-,:/-Y
LwTdmR
//打印回应的头信息 @!j6y(@
public void logResponseHead(HttpURLConnection con) 8TG|frS
{ UG_PrZd
for(int i=1;;i++) h?$J;xn
{ E0l&d
String header=con.getHeaderFieldKey(i); 2(x| %
if(header!=null) X @pm!c#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ExN$J
Utility.log(header+" : "+con.getHeaderField(header)); t: oQHhO?
else Ujlbcv6+
break; Ekik_!aB
} fJ0V|o
} q`.=/O'
d[5v A/8O
[La}h2gz
public void splitterStop() D?8(n=#[
{ x%9Ca)r?}
bStop = true; zY7M]Az
} Q`NdsS2
:WsHP\r
7+}WU4
} [8q`~S%-]
XT*/aa-1'
Z_edNf}|
/* D(TG)X?
**FileAccess.java 9+$IulOvk
*//文件访问(定位，写) 2+?W{yAEi
package NetFox; *DXX*9 0
import java.io.*; ?B$L'i[l
F6{/iF
~-y&C%
public class FileAccessI implements Serializable{ {0np
PkZ1Db
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 U$y wO4.
RandomAccessFile oSavedFile; T8)X?>CIW
long nPos; 3$Vx8:Rhdn
-ah)/5j
Qx3eEt@X5]
public FileAccessI() throws IOException !`4ie
{ 1RX-`"^+
this("",0); )db:jPkwd
} V~ MsGj
-3ANNj
k3e6y
public FileAccessI(String sName,long nPos) throws IOException 6Vncr}
{ G<k.d"<
oSavedFile = new RandomAccessFile(sName,"rw"); mPqKk
this.nPos = nPos; :-<30LS$
oSavedFile.seek(nPos); nqx0#_K-E
} 63_#*6Pv28
Ayv:Pv@
5''k|B>
public synchronized int write(byte[] b,int nStart,int nLen) cH$(*k9%M
{ dtTfV.y4w
int n = -1; ]Hq,Pr_+
try{ akPd#mf
oSavedFile.write(b,nStart,nLen); Iw`|,-|
n = nLen; jcvq:i{
} _?y3&4N)
catch(IOException e) |Kjfh};-C
{ 8B-mZFXpK
e.printStackTrace (); n7Bv~?DM
} mF!4*k
%Tu(>vnuj
Y~Vc|zM^(
return n; |pbetA4&
} _(~LXk^C
Y2tBFeWY
!4gHv4v;
} n[r1h=?j3
.fhfb\$
QVkji7)ZT
/* S.`hl/
**SiteInfoBean.java z C$F@
*/ F(Zf=$cx
package NetFox; iPY)Ew`Im
]dl.~;3~~
"PWGtM:L8Y
public class SiteInfoBean { Z__fwv.X[
| oM`
k%\y,b*
private String sSiteURL; //Site's URL )F\kGe
private String sFilePath; //Saved File's Path fv+d3s?h
private String sFileName; //Saved File's Name <HTz
private int nSplitter; //Count of Splited Downloading File pDJN}XtjT
r#_0_I1[
R]Z#VnL@qz
public SiteInfoBean() !>ZBb\EyK
{//nSplitter的缺省值为5 fx4#R(N
//default value of nSplitter is 5 ]q4LNo
this("","","",5); ZREy I(_
} {Y=k`t,
AZ^>osr
*?C8,;=2r
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4M|C>My
{ {06ClI
sSiteURL= sURL; fF>hca>
sFilePath = sPath; Z%LS{o~LK.
sFileName = sName; ]N0B.e~D
this.nSplitter = nSpiltter; )?B-en\
jk_yrbLc
xhCQRw
} uPN^o.,/.
_D@QsQ_Z
} _];yw
public String getSSiteURL() Wd(|w8J{a
{ \fSruhD
return sSiteURL; vN@04a\h
} N+5f.c+S-
VKu_l
<0hVDk~
public void setSSiteURL(String value) K4E2W9h
{ #lSGH 5Fp?
sSiteURL = value; >ifys)wg>
} zVe,HKF/
&U=_:]/
#nft{AN
public String getSFilePath() -kP2Brm
{ 9-&@Y
return sFilePath; .YH#+T'
} {|j-e{*
$AvaOI.l
K.&6c,P]
public void setSFilePath(String value) 6Fk[wH7
{ BT;1"l<
sFilePath = value; '43Uv
} <nV3`L&]
mr_NArF
;}KJ[5i-V
public String getSFileName() 4AvIU!0w
{ Z\QNn
return sFileName; 3m21n7F4*
} Sx Bo%
;0$qT$,
)' ,dP)b
public void setSFileName(String value) -`Zk`s|!
{ =%>E8)Jb
sFileName = value; jJ@@W~/)B
} Rf>V]R
rTJU)4I^h
$ntC{a>&
public int getNSplitter() XgKYL<k?S
{ .{bT9Sc5
return nSplitter; s2 aFme
} i?#U>0!
I{H!KrM!
&Q\k`0vzVB
public void setNSplitter(int nCount) FOPmvlA\-<
{ H.l WHM+H4
nSplitter = nCount; Po\+zZjo
} 8(A k
} w)YTHY(k;
&?y|Pn
YY7dw:>e/
/* \MmB+'f&R
**Utility.java \Km+>G
*/ 7<2?NLE8*
package NetFox; eCg|@d%D
j *N^.2
kZ:~m1dd
public class Utility { -W})<{End
#a8i($k{e
1OqVNp%K
public Utility() f_hG2Sk
{ $m+Pl[s
*_Pkb.3R
jlUT9Zp
} s <$*A;t
qe0ZM-C_
//线程睡眠 cyL|.2,
public static void sleep(int nSecond) oK"#*n
{ Av/y
try{ [f$pq5f='
Thread.sleep(nSecond); &mA{_|>
} z^%`sUgP
catch(Exception e) =)Goip
{ ::/vDUDc
e.printStackTrace (); y>g`R^^
} IY(;:#l
} SQuW`EHBgs
t +CU
//日志 n.P$E
public static void log(String sMsg) Ye>+
{ )$2h:dw_
System.err.println(sMsg); g%4=T~
} lgHzI(
. vea[
-#AO4xpI
public static void log(int sMsg) 3[m~6Ys
{ pSpxd|k
System.err.println(sMsg); #N\<(SD/
} #q?:Act
} K*j1Fy:
*NIhYg6
xT+@0?|F
/* "+4r4
**TestMethod.java &v+Hl^
*/ ADA*w 1
package NetFox; oR<;Tr~{q
-$D#u
7{f{SIB
public class TestMethod { s! sG)AR.J
j2%#xZ{33
mi sPJO&QD
public TestMethod() DJRr
{ ///xx/weblogic60b2_win.exe #)KQ-x,
try{ P?iQ{x}w~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 93Qx+oK]
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); xn7bb[g;
SiteFileFetch fileFetch = new SiteFileFetch(bean); U }}E E~W
fileFetch.start(); NX<Q}3cC
} n(Ry~Xu_
catch(Exception e){e.printStackTrace ();} [>kzQYT[
Yb>A?@S
bLz('mUY
} v,c:cKj
DEKO]i
t~]tw
public static void main(String[] args) 3W?H^1t
{ >vQKCc|93
new TestMethod(); =,W~^<\"
} 8';huq@C{
} /KCIb:U
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