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)); .Ir5gz
} =V(I
for(int i=0;i<nEndPos.length-1;i++) d>2>mT$U
{ f"z96{zo
nEndPos = nStartPos[i+1]; @X|CubJ
} E;k'bz
nEndPos[nEndPos.length-1] = nFileLength; 9%|!+!j
} .QW89e,O3
} jfk`%CEk=
fF;-d2mF
Ok9XC <Xu
//启动子线程 ;asB@Q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >=wlS\:"
for(int i=0;i<nStartPos.length;i++) NT:p6(s^
{ /aP`|&G,)
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DvU(rr\p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), m+zzhv1
nStartPos,nEndPos,i); EiSS_Lc
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G>"w$Us
fileSplitterFetch.start(); <f1Pj
} Y7= *-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ig~lD>dnr'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Or0=:?4`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", t;{/Q&C
nEndPos = " + nFileLength); 9|fg\C
// fileSplitterFetch[nPos.length-1].start(); .^ soX}
=}F &jl
sT|8a
//等待子线程结束 IF<pT)
//int count = 0; awGI|d
//是否结束while循环 (z\@T`6`
boolean breakWhile = false; %+qD-{&
"d9"Md0k
LJ9^:U
while(!bStop) XB zcbS+
{ .cjSgK1
write_nPos(); z.--"cF
Utility.sleep(500); Ovh[qm?Z
breakWhile = true; \IIR2Xf,K
I!~5.
k68\ _NUL
for(int i=0;i<nStartPos.length;i++) -b8Vz}Y
{ ckS.j)@.c
if(!fileSplitterFetch.bDownOver) -m3O\X
{ V^[o{'+
breakWhile = false; ;~3CuN8
break; 9ELLJ@oNC
} 82{Lx7pI
} ,dP-sD;<
if(breakWhile) *MglX<
break; ~J)_S' #
<`}Oi5nW
1Jjay#
//count++; E)7vuWOO
//if(count>4) 9t9x&.A
// siteStop(); unKi)v1
} (]>=y
CNwIM6t
;N#d'E\
System.err.println("文件下载结束！"); E9i M-Lw
} -W<x|ph U
catch(Exception e){e.printStackTrace ();} Yxp.`
} QX-%<@
?#da4W
{1Z8cV
//获得文件长度 Dyyf%'\M
public long getFileSize() hOG9
{ [@(M%
int nFileLength = -1; Bvb.N$G
try{ E<y0;l?H<
URL url = new URL(siteInfoBean.getSSiteURL()); u_shC"X:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B&3oo
httpConnection.setRequestProperty("User-Agent","NetFox"); Iy% fg',%
L)p*D(
kZ~0fw-
int responseCode=httpConnection.getResponseCode(); <b!nI N
if(responseCode>=400) qbrY5;U
{ 5)bf$?d
processErrorCode(responseCode); ZCVwQ#Xe+
return -2; //-2 represent access is error )RG@D\t,
} %5Q5xw]w3
p=sLKnLmZ
+uZ,}J
String sHeader; noJ5h|
|*W_
<pyLWmO
for(int i=1;;i++) ~$cz`A
{ B >2"O
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); dY[ XNP
//Utility.log(in.readLine()); 2[-@ .gH
sHeader=httpConnection.getHeaderFieldKey(i); : .Y
if(sHeader!=null) [;~:',vHQf
{ 4LO4SYW7
if(sHeader.equals("Content-Length")) YW9r'{(D(I
{ B8_)I.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); iYJ:P
break; <?yf<G'$
} dp;;20z
} F<H[-k*t/
else Av6=q=D
break; 4j+FDc`
} ])Rs.Y{Q5
} JWQd/
catch(IOException e){e.printStackTrace ();} 5yBaxw`
catch(Exception e){e.printStackTrace ();} qM}Uk3N0
7m='-_w)?w
r?Q`b2Q
Utility.log(nFileLength); xgeDfpF'
4u0\|e@a
d^b(Uo=$
return nFileLength; z 3((L
} TNun)0p
+pMa-{
V;}kgWc1
//保存下载信息（文件指针位置） V}=%/OY?
private void write_nPos() 2yB)2n#ut
{ ~hiJOaCzM
try{ 1V?)T
output = new DataOutputStream(new FileOutputStream(tmpFile)); q+<<Ku(20
output.writeInt(nStartPos.length); n/]w!
for(int i=0;i<nStartPos.length;i++) Em6P6D>S>,
{ vl}fC@%WRI
// output.writeLong(nPos); TEB<ia3+
output.writeLong(fileSplitterFetch.nStartPos); }7Lo}}
output.writeLong(fileSplitterFetch.nEndPos); d6RO2^
} n`v;S>aT
output.close(); zt,Tda4Y
} %*:X FB
catch(IOException e){e.printStackTrace ();} Qk`ykTS!
catch(Exception e){e.printStackTrace ();} iB-h3/
} hv.33l
$+'bRUo
cl\Gh
//读取保存的下载信息（文件指针位置） @9$u!ny0
private void read_nPos() ,EsPm'`?A/
{ b{+7sl
try{ U-h'a: K
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |aWeo.;c
int nCount = input.readInt(); KkD.n#A
nStartPos = new long[nCount]; ^lw0} i
nEndPos = new long[nCount]; WC0gJy
for(int i=0;i<nStartPos.length;i++) ]\TYVv)
{ KH=4A-e,0
nStartPos = input.readLong(); xvpCOoGsz
nEndPos = input.readLong(); PeU>h2t
} _Fc :<Ym?
input.close(); =@ SJyW
} 8)KA {gN}
catch(IOException e){e.printStackTrace ();} BIJlU(aF
catch(Exception e){e.printStackTrace ();} $nf5bo/;
} g#W/WKvM
s*XE
UYw_k\
private void processErrorCode(int nErrorCode) $~^Y4 } m
{ <t~RGn3
System.err.println("Error Code : " + nErrorCode); k 'CM^,F&
} O\~/J/u <
^k#.;Q#4
D6Q6yNE
//停止文件下载 5>S=f{ghFw
public void siteStop() ng0tNifZ;
{ --D&a;CO}
bStop = true; A,H|c="
for(int i=0;i<nStartPos.length;i++) M'(4{4rC
fileSplitterFetch.splitterStop(); (B/od#nU
W~W`fm
6cQ)*,Q
} "J.7@\^ h/
} 7NQ@q--3s
//负责部分文件的抓取 Q85Y6',
**FileSplitterFetch.java [\_#n5
*/ 'L k&iph
package NetFox; 9e aqq
'c[|\M!u
GS*Mv{JJ
import java.io.*; ,)svSzR
import java.net.*; ]QqT.z%B
dRhsnT+KX
\c1NIuJR
public class FileSplitterFetch extends Thread { 178u4$# b
:6T8\W
DQ08dP((v
String sURL; //File URL 0m&
long nStartPos; //File Snippet Start Position Hyn*O)q!
long nEndPos; //File Snippet End Position K|a^<| S
int nThreadID; //Thread's ID ;:`0:Ao.
boolean bDownOver = false; //Downing is over X:/Y^Xu
boolean bStop = false; //Stop identical 6he (v
FileAccessI fileAccessI = null; //File Access interface Y%GIKtP
fR^aFT
:nLhg$wMs
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s{Wj&.)M
{ 1woBw>g
this.sURL = sURL; {hRM=f7
this.nStartPos = nStart; 9im<J'
this.nEndPos = nEnd; /c4@QbB
nThreadID = id; o6b\ w
fileAccessI = new FileAccessI(sName,nStartPos);//定位 XX9u%BZ~
} o$XJSz|6
f7du1k3
H)5V \
public void run() MJ%gF=$X
{ Q($.s=&l;
while(nStartPos < nEndPos && !bStop) Qzh`x-S
{ ;ND)h pD+
8lJMD %Df:
)=9EShz!
try{ O_~vl m<#
URL url = new URL(sURL); C)H1<Br7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tR{@NFUcu
httpConnection.setRequestProperty("User-Agent","NetFox"); $LXz Q>w9
String sProperty = "bytes="+nStartPos+"-"; {E3329t|'
httpConnection.setRequestProperty("RANGE",sProperty); lYq/ n&@_1
Utility.log(sProperty); lk[BS*
%uUQBZ4
s9\HjK*+
InputStream input = httpConnection.getInputStream(); n7$21*,
//logResponseHead(httpConnection); No(p:Snbo
p]^?4
]!mC5Ea
byte[] b = new byte[1024]; ;*AKeI2
int nRead; [W*xPXr*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %Jb/HWC[
{ bAkCk]>5
nStartPos += fileAccessI.write(b,0,nRead); O\z]1`i*o
//if(nThreadID == 1) wU $j/~L
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2<X.kM?N{B
} \~4IOu
+#wh`9[wBt
H%&e[PU
Utility.log("Thread " + nThreadID + " is over!"); 24; BY'
bDownOver = true; gQ8FjL6?
//nPos = fileAccessI.write (b,0,nRead); x[m&ILr
} I}!ErV
catch(Exception e){e.printStackTrace ();} E4;@P']`
} :,~]R,tJQ
} 7wA.:$
xn BL{ []
O)EA2`)E
//打印回应的头信息 Ug~]!L
public void logResponseHead(HttpURLConnection con) m,1Hlp
{ AzlZe\V?)~
for(int i=1;;i++) um}%<Cy[
{ Z<ABK`rEO
String header=con.getHeaderFieldKey(i); R>#BJ^>=
if(header!=null) '^#=,+ A
//responseHeaders.put(header,httpConnection.getHeaderField(header)); V!XT=Ou?6
Utility.log(header+" : "+con.getHeaderField(header)); fa:V8xa
else qHtonJc
break; x<lY&KQ0
} XqxmvN
} [>#@?@x`P
rq]zt2
#l<un<
public void splitterStop() 9irT}e
{ tOEY|
bStop = true; mcgkNED
} lq[o2\
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#@^mA{Dt5
} m&&Y=2
6_vhBYLf
Rg,]du u?
/* s ~Xa=_+D
**FileAccess.java f*tKj.P
*//文件访问(定位，写) U1,f$McZs
package NetFox; #eZm)KFQg
import java.io.*; Zp'q;h_
a|u&N:v7B
-rXo}I,VI
public class FileAccessI implements Serializable{ A6faRi703
:rcohzfa
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 W}0cM9 g
RandomAccessFile oSavedFile; ~REP@!\r^
long nPos; =o? Q0
mQiVTIP3[O
]?"1FSu-8r
public FileAccessI() throws IOException +.Cx.Nf(
{ >v9@p7Dn
this("",0); %'`L+y
} Xpp%j
Mb +
q8-*3K
public FileAccessI(String sName,long nPos) throws IOException //O9}-
{ Ku3/xcu:My
oSavedFile = new RandomAccessFile(sName,"rw"); o / i W%
this.nPos = nPos; VQe@H8>3
oSavedFile.seek(nPos); yG~7Xo5
} wrJ:jTh
<JkmJ/X
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public synchronized int write(byte[] b,int nStart,int nLen) 8Vf]K}d
{ fHc/5uYW
int n = -1; ;mtv
try{ )o\U4t
oSavedFile.write(b,nStart,nLen); ?K>=>bS^h
n = nLen; 'v?"TZ
} ?]In@h-
catch(IOException e) >^|(AzS
{ AhauNS^"{R
e.printStackTrace (); [/'=M h
} WPXLN'w+
jYJRG<*e
)&$p?kF
return n; 1.6Y=Mh=i[
} z pV+W-j]
JA(M'&q4
KvtX>3#qM
} "H"4]m1Wc
YgfQ{3^I
iLR^V!
/* PEIf)**0N
**SiteInfoBean.java ,lUr[xzV
*/ Z?AX
package NetFox; hOH DXc"
v[t*CpGd
Q/u1$&1
public class SiteInfoBean { Bq 9Eu1
m:4Ec>?e
c*:H6(u
private String sSiteURL; //Site's URL ?jy6%Y#,i
private String sFilePath; //Saved File's Path F?EAIL
private String sFileName; //Saved File's Name =xX)2h
private int nSplitter; //Count of Splited Downloading File blHJhB&8
}_GI%+t
< X&{6xu
public SiteInfoBean() } 0^wJs
{//nSplitter的缺省值为5 Z<M?_<3
//default value of nSplitter is 5 jJU9~5i?
this("","","",5); l$mfsm|{:
} SIr^\iiOB
B33H,e)
=Ti[Q5SZ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) L-V+`![{
{ 4y$tp18
sSiteURL= sURL; 2C@s-`b
sFilePath = sPath; kntM
sFileName = sName; .*acw
this.nSplitter = nSpiltter; 8&2W^f5
EKTn$k=
z:a%kZQ!0
} XZ1oV?Z4
W:V:Ej7 h
uFH ]w]X
public String getSSiteURL() r)Dln5F
{ ImZ!8#
return sSiteURL; )e6)~3[^
} fH6mv0
WY3D.z-</
s+RSAyU
public void setSSiteURL(String value) mO|YX/>
{ p%?m|(4f
sSiteURL = value; co-dq\P
} :i8B'|DN5
"pLWJvj6-
<f+9wuZ
public String getSFilePath() ehe;<A
{ $V?h68[c
return sFilePath; 6Rcl HU
} }_vUsjK
f:_mrzz
6r3.%V.&
public void setSFilePath(String value) LH_rc
{ +#Q\;;FNP
sFilePath = value; `eXTVi|0"~
} &Bfgvws;
l*(Ml= O{
.W/#$s|X\
public String getSFileName() N# ?}r>W3
{ .{}=!>U2
return sFileName; h:qt?$]J
} hI Q 2s
|2'u@<(Z/
q` Z_Bw
public void setSFileName(String value) ZQV,gIFys
{ h|Z%b_a
sFileName = value; /%4wm?(eA
} P9/Bc^5'
WVa#nU^
|?=a84n1l
public int getNSplitter() vC1D}=Fp
{ pY T^Ug
return nSplitter; C 7e
} |:jka
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7%x 3o#&
public void setNSplitter(int nCount) Dx1w I
{ 5&QDZnsl
nSplitter = nCount; (^)" qsB
} B<}0r4T}
} ,KO_h{mI<
+&j&es
[h;&r"1
/* #MwNyZ
**Utility.java 6Uik>e7?
*/ njoU0f1`
package NetFox; EqB3f_
G{C27k>wa
,k=1'7d
public class Utility { hynX5,p;.
dd=';%?
G,]%dZHe
public Utility() RqnT*
{ p#fd+
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93+p~?
} gs?=yNL
[->uDbtzL
//线程睡眠 %n7mN])
public static void sleep(int nSecond) )08mG_&atL
{ bU+ z(Eg6
try{ 1_Ag:>#X
Thread.sleep(nSecond); U!xOJ
} nS`DI92I
catch(Exception e) N=hhuKt]
{ n@ rphJb
e.printStackTrace (); oI/jGyY;
} LEJ8 .z6$
} 9"%ot=)
;uK">L[u'
//日志 nGvWlx
public static void log(String sMsg) `EjPy>kM
{ _h2s(u >\
System.err.println(sMsg); E,fG<X{
} iR`c/
e.<y-b?
d 6$,N|
public static void log(int sMsg) 4Z"JC9As
{ vi:IO
System.err.println(sMsg); Ev'BmDk
} ,cg%t9
} fsr0E=nV
dDeImSeV
M:*^k
/* ;K+'J0
**TestMethod.java a*fUMhIi
*/ TGe)%jZ
package NetFox; fQ@k$W\
\4B2%H
/'S@iq
public class TestMethod { n,.ZLuBEX
4Em$L]7
68pB*(i
public TestMethod() [l9iWs'M
{ ///xx/weblogic60b2_win.exe Fo0dz
try{ kOycS
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); v o9Fj
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); O_n) 2t(c?
SiteFileFetch fileFetch = new SiteFileFetch(bean); acXB vs
fileFetch.start(); No1*~EQ
} H$j`75#u?-
catch(Exception e){e.printStackTrace ();} lN<,<'&^.
VXpbmg!{S
P%-@AmO^_
} 5V{ B,T
q!5 *)nw"
fCq
public static void main(String[] args) D02_ Jrg
{ ee9nfvG-
new TestMethod(); $d[xSwang
} %^r}$mfy:0
} @H?_x/qBT
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