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)); DvKM[z3j
} 'p80X^g
for(int i=0;i<nEndPos.length-1;i++) 6@t4pML
{ *RD9gIze
nEndPos = nStartPos[i+1]; R#"kh/M
} - /]ro8V$
nEndPos[nEndPos.length-1] = nFileLength; @0;9.jml,
} (_^g:>)Cs
} Ia=wf"JS)
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),(ejRP'r
//启动子线程 <x,u!}5J
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `(vgBz`e[
for(int i=0;i<nStartPos.length;i++) #'^!@+)
{ dE7 kd=.o
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Og4 X3QG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3k`"%R.H
nStartPos,nEndPos,i); Ok/~E
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z3<>Z\6D
fileSplitterFetch.start(); <*3{Twa1T
} MUh)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 22"M#:r$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]tA39JK-i
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", bHH{bv~Z
nEndPos = " + nFileLength); UO47XAO
// fileSplitterFetch[nPos.length-1].start(); !@{_Qt1
IHZ WNT2
^3B{|cqf
//等待子线程结束 M=HW2xn
//int count = 0; .+t{o[
//是否结束while循环 ?7 e|gpQ|
boolean breakWhile = false; 6a[D]46y,2
}@J&yrqg
y44FejH(v
while(!bStop) f50qA;7k
{ [X ]\^
write_nPos(); O`~G'l&@T
Utility.sleep(500); y8HLrBTza
breakWhile = true; yw^t6E
}jBr[S5
0N$tSTo.-<
for(int i=0;i<nStartPos.length;i++) M p:c.
{ \j !JRD+j
if(!fileSplitterFetch.bDownOver) K++pH~o
{ QMea2q|3$
breakWhile = false; 5Al59]
break; \~UyfVPRT
} 3P3x^NI
} I~H:-"2
if(breakWhile) '31pb9@fH
break; !SEHDRp
yx"xbCc#
Un@B D}@\
//count++; ,LKY?=T$z
//if(count>4) .",E}3zn
// siteStop(); 6[,*2a8
} }WS%nQA
REDh`Wd
${0+LhST
System.err.println("文件下载结束！"); EQ1wyKZS2g
} Iz,a Hrq
catch(Exception e){e.printStackTrace ();} |C?<!6.QmV
} "P\k_-a'
8.HqQ:?&2t
P$S>=*`n U
//获得文件长度 _?#}@?
public long getFileSize() Yf&x]<rkCp
{ ]S9~2;2^,
int nFileLength = -1; x!fvSoHp
try{ Ar7vEa81
URL url = new URL(siteInfoBean.getSSiteURL()); LL|$M;S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !q=ej^(S
httpConnection.setRequestProperty("User-Agent","NetFox"); "gjy+eosY
Ta`=c0
Bm2"} =
int responseCode=httpConnection.getResponseCode(); [U@#whEO
if(responseCode>=400) tNg}:a|J
{ y3@R>@$
processErrorCode(responseCode); }eb}oK
return -2; //-2 represent access is error <iVn!P
} \72(d
ax0RtqtR&
pt<!b0G
String sHeader; PCDsj_e
=UYZ){rt9E
n,}\;Bp
for(int i=1;;i++) }/q]:3M|
{ 7.-Q9xv
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); TbbtD"b?
//Utility.log(in.readLine()); }wRHNBaEB
sHeader=httpConnection.getHeaderFieldKey(i); ~6L\9B)
if(sHeader!=null) jPU:&1(_ n
{ Mu$9#[/
if(sHeader.equals("Content-Length")) mu`h6?v
{ xU+c?OLi
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |n3fAN
break; {^zieP!
} /\P3UrQ&]
} unu%\f>^4
else ee}&~%
break; XMo#LS
} NF+^
} ]pr(hk
catch(IOException e){e.printStackTrace ();} ={P
catch(Exception e){e.printStackTrace ();} }qU(G3
s{x{/Bp(KK
A+v6N>}*
Utility.log(nFileLength); veX#K#
'&?cW#J?
W(U:D?e
return nFileLength; NT+%u-
} 5%M 'ewu
Ve\^(9n
M ^gva?{
//保存下载信息（文件指针位置） /NRdBN
private void write_nPos() 9>,$q"M}?
{ nP`#z&C
try{ _"Yi>.{]
output = new DataOutputStream(new FileOutputStream(tmpFile)); w5zrEk#
output.writeInt(nStartPos.length); =_~bSEqyRI
for(int i=0;i<nStartPos.length;i++) trD-qi
{ #+dF3]X(&
// output.writeLong(nPos); <NRW^#g<x
output.writeLong(fileSplitterFetch.nStartPos); 2MS-e}mi
output.writeLong(fileSplitterFetch.nEndPos); Q'-g+aN
} 9w\yWxl
output.close(); i2$7nSQ9
} cb|cYCo5
catch(IOException e){e.printStackTrace ();} ;Z:zL^rvn
catch(Exception e){e.printStackTrace ();} .3Ex=aQcX
} kB~KC-&O
ig G8L
`-Yo$b;:
//读取保存的下载信息（文件指针位置） G&ZpQ)
private void read_nPos() .A 12Co
{ 6,Aj5jG
try{ #a7 Wx}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 4rXjso|
int nCount = input.readInt(); j;%RV)e
nStartPos = new long[nCount]; E(t:F^z&D
nEndPos = new long[nCount]; X{2))t%
for(int i=0;i<nStartPos.length;i++) bWp40&vx
{ Z?@1X`@
nStartPos = input.readLong(); W>jgsR79M
nEndPos = input.readLong(); VI:EjZ/|a
} +-8u09-F
input.close(); o0SQJ1.a$
} /m#!<t7
catch(IOException e){e.printStackTrace ();} [+7Nu
catch(Exception e){e.printStackTrace ();} ruqx#]-
} (y^[k {#
y9<]F6TT
NR98I7
private void processErrorCode(int nErrorCode) c{7<z9U
{ 'dTJE--@
System.err.println("Error Code : " + nErrorCode); a+wc"RQ |
} h5@v:4Jjo~
R 2.y=P8N
#~ikR.-+Eq
//停止文件下载 v-^7oai
public void siteStop() ^5BLuN6
{ ,Oqd4NS
bStop = true; I,rs&m?/m
for(int i=0;i<nStartPos.length;i++) Ky6.6Y<.|
fileSplitterFetch.splitterStop(); Mv\odf\]
*^h$%<QI
s#f6qj
} N\Nwmx
} ]mED3#
//负责部分文件的抓取 'a&(r;
**FileSplitterFetch.java [xaglZ9HNo
*/ FrPpRe%!
package NetFox; ]g}Tqf/N%
kaKV{;UM
0/r\#"+XT
import java.io.*; S`N_},
import java.net.*; 'Cc(}YY0C
\1^qfw
`#v(MK{9+V
public class FileSplitterFetch extends Thread { HizMjJ|
="M7F0k
OfSy_#aEK
String sURL; //File URL ]7#@lL;'0
long nStartPos; //File Snippet Start Position ;t^8lC?>V
long nEndPos; //File Snippet End Position d{~5tv- H
int nThreadID; //Thread's ID NrC(.*?m
boolean bDownOver = false; //Downing is over w_*UFLMSqR
boolean bStop = false; //Stop identical MV+S.`R
FileAccessI fileAccessI = null; //File Access interface muD7+rn?&
wK0= I\WN9
z3 zN^ZT
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Ax'jNol
{ b[mAkm?9+1
this.sURL = sURL; z}L3//
this.nStartPos = nStart; *58`}]
this.nEndPos = nEnd; g91X*$`]
nThreadID = id; )ifEgBT
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %Pz'D6 /
} d|nJp-%V
O{B[iy(C
Sk'S`vH
public void run() upD2vtU
{ a0s6G3J+9
while(nStartPos < nEndPos && !bStop) <G5d{rKZ
{ wUd6xR
!jV}sp<Xp
R0 g-
try{ jK#[r[q{
URL url = new URL(sURL); `L-GI{EJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'dnTu@mUT
httpConnection.setRequestProperty("User-Agent","NetFox"); ]A;{D~X^w
String sProperty = "bytes="+nStartPos+"-"; FIB 9W@oao
httpConnection.setRequestProperty("RANGE",sProperty); 3EM=6\#q
Utility.log(sProperty); "zT#*>U
E"EBj7<s
eyx;8v cM
InputStream input = httpConnection.getInputStream(); xz@/^Cj
//logResponseHead(httpConnection); &=seIc>x@
Z+zx*(X
(TQx3DGq
byte[] b = new byte[1024]; 9M$=X-
int nRead; E7XFt#P.
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) F?+K~['i
{ dy4! >zxF
nStartPos += fileAccessI.write(b,0,nRead); Nb))_+/
//if(nThreadID == 1) ;au-NY
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *?k~n9n5U
} =Ws-s f]
JN9 W:X.
&&N]u e@>
Utility.log("Thread " + nThreadID + " is over!"); xB1Oh+@i
bDownOver = true; yJt0KUw@!
//nPos = fileAccessI.write (b,0,nRead); t)yWQV
} XQ+KI:g2
catch(Exception e){e.printStackTrace ();} ^|z
} D6 2xC5
} ZfzUvN&!
!'4HUB>+
}CR@XD}[
//打印回应的头信息 LuM[*_8
public void logResponseHead(HttpURLConnection con) RHV&m()Q
{ @"`J~uK
for(int i=1;;i++) [")3c)OH|
{ MroJ!.9
String header=con.getHeaderFieldKey(i); .A: #l?
if(header!=null) ,ux?wa+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4g}eqW
Utility.log(header+" : "+con.getHeaderField(header)); %p5%Fs`sd
else &cty&(2p
break; ail%#E8
} g~5$X{
} 99'e)[\
l;4},N
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public void splitterStop() <&n\)R4C1
{ P4{8pO]B
bStop = true; ,_K /e
} ;\N{z6
YlI/~J
?v]EXV3
} j@jaFsX|
.OLm{
3`ov?T(H
/* 3},0b8};
**FileAccess.java Tw:j}ERq
*//文件访问(定位，写) {> T r22S
package NetFox; `lAe2l^
import java.io.*; 7Eoa~
IMaa#8,
3)jFv7LAU
public class FileAccessI implements Serializable{ _#6_7=g@s6
))y`q@
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 uJQ#l\t
RandomAccessFile oSavedFile; 9#K,@X5 j
long nPos; rJ2yi6TB\
FerQA9K)x
~YQC!x
public FileAccessI() throws IOException 8lG@8tbW^
{ 'CE3 |x\%K
this("",0); 7(RtPLpZ
} !j'9>G{T
~p9nAACU
^gP pmb<x
public FileAccessI(String sName,long nPos) throws IOException G}!dm0s$
{ .M3]\I u
oSavedFile = new RandomAccessFile(sName,"rw"); 3q{op9_T7
this.nPos = nPos; J2rw4L
oSavedFile.seek(nPos); \k?Fu=@
} [PVem
Ce:2Tw
FW](GWp`:
public synchronized int write(byte[] b,int nStart,int nLen) -4 ~(*
{ $)UMRG
int n = -1; 60 D0z
try{ *G'R+_tdE
oSavedFile.write(b,nStart,nLen); T8nOb9Nrj
n = nLen; dMo456L
} oD0WHp
catch(IOException e) 0K+a/G@ n\
{ k!9LJ%Xh
e.printStackTrace (); dD%Sbb
} >_R,^iH"
@|3PV
p6UPP|-S
return n; %9bf^LyD
} QqpXUyHp[
$K_G|Wyi
^0 zWiX
} >!o||Yn
|f9fq~'1e
yeI((2L@E2
/* %(f&).W
**SiteInfoBean.java dA[MjOd3
*/ L?aaR%6#
package NetFox; tc.`P]R
+(a}S$C
bSK> p3
public class SiteInfoBean { ^p@R!228
`5J`<BPs
l"T{!Oq
private String sSiteURL; //Site's URL p#k>BHgnF
private String sFilePath; //Saved File's Path )GbVgYkk
private String sFileName; //Saved File's Name UW!*=?h
private int nSplitter; //Count of Splited Downloading File Ub>Pl,~'
z}772hMB
0uw3[,I
public SiteInfoBean() cJIA/HQe
{//nSplitter的缺省值为5 ,WvCslZ
//default value of nSplitter is 5 (x+C=1,
this("","","",5); #b^x!lR
} s":\>
~8rVf+bg3
-W6r.E$mC
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <KBzZ !n5
{ :)~idVlV
sSiteURL= sURL; ;*~y4'{z
sFilePath = sPath; /o/0 9K
sFileName = sName; .aA8'/
this.nSplitter = nSpiltter; f:w#r.]
|i/Iv
l.Psh7B2
} Ao2m"ym
bwr}Ge
O8!> t7x
public String getSSiteURL() nVSuvq|S
{ -pF3q2zb
return sSiteURL; 1@i 8ASL
} 5O7x4bY
{6/Yu:;
r+#!]wNPe
public void setSSiteURL(String value) ;|.~'':
{ ]<Ugg
sSiteURL = value; JQ[~N-
} c@uNA0 p
!awsQ!e|
CyWaXp65
public String getSFilePath() hwon^?
{ &*w)/W
return sFilePath; t V]BcDp
} _&]B
)q+Qtz6D
Ah|,`0dw
public void setSFilePath(String value) h_SDW %($
{ dHAI4Yf4U
sFilePath = value; Em(&cra
} 0\Q/$#3
;:^^Qfp
xUKn
public String getSFileName() #RyX}t X,
{ 1TuN
return sFileName; @$e!|.{1q
} fD1a)Az
F$!K/Mm[
F5Xj}`}bq
public void setSFileName(String value) ZQ0R3=52r
{ &idPO{G
sFileName = value; |3h-F5V)
} BS6UXAf{|Z
'f?=ks<
]csfK${
public int getNSplitter() rEM#J"wF
{ "< c,I=A
return nSplitter; A<+veqb4
} ?xb4y=P7
3=)!9;uY
pKxq\U
public void setNSplitter(int nCount) pow.@
{ o-m9}pV
nSplitter = nCount; 2brxV'tk
} >@mvb@4*
} $4&%<'l3I
E&wz0d;gf
Pf4b/w/
/* AMm)E
**Utility.java `E4+#_ v
*/ q>E[)\+y
package NetFox; {zri6P+s
Ul/Uk n$
x9U(,x6r
public class Utility { q\`0'Z,
"6<L) 8
Z<Pf[C
public Utility() >[D(<b(U&
{ N1vPY]8
}1sFddGVt
):c)$$dn
} 4|]0%H~n6
z+k[HE^S
//线程睡眠 'Pm.b}p<
public static void sleep(int nSecond) {?zBc E:
{ <uYeev%
try{ mF@)l]UZ'
Thread.sleep(nSecond); 'Y%@fZf x
} p:/#nmC<
catch(Exception e) z :q9~
{ ?4^8C4
e.printStackTrace (); u@{z xYn
} JJ+A+sfdk
} .:nV^+)
+4r.G(n),
//日志 ,?k~>,{3
public static void log(String sMsg) M(8Mj[>>Rj
{ Wt,t5
System.err.println(sMsg); _?YP0GpU
} v"K #
xaSg'8-
68 *~5]
public static void log(int sMsg) T0Kjnzs
{ }5??n~:*5
System.err.println(sMsg); *\M$pUS{
} @}8~TbP
} >B~vE2^tQ~
_^(}6o
XP|qY1
/* JR_s-&GaM
**TestMethod.java "7. lsL5
*/ RY4b<i3
package NetFox; 9!kH:Az[p
3%NbT
;G=:>m~
public class TestMethod { jO9w7u6
w9c^IS
G8Qo]E9-/
public TestMethod() I.qP$j
{ ///xx/weblogic60b2_win.exe iYE7BUH=
try{ iL](w3EM
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); r@.3.Q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); j0eGg::
SiteFileFetch fileFetch = new SiteFileFetch(bean); pp!>:%
fileFetch.start(); @TWtM#
} <8SRt-Cr
catch(Exception e){e.printStackTrace ();} DJu&l
8!!iwmH{
Z`9yGaTO
} j0]|$p
D{J+}*y
V.f'Cw
public static void main(String[] args) mH/$_x)o
{ 6 pQbh*
new TestMethod(); 2^TJ_xG~
} ^UJ#YRzi
} HfN:oww
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