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)); Fv*QcB9K
} ]Ok'C"V(j
for(int i=0;i<nEndPos.length-1;i++) (S4HU_,88
{ L[Ot$
nEndPos = nStartPos[i+1]; Nw*F1*v`
} 61b*uoq0w?
nEndPos[nEndPos.length-1] = nFileLength; CiGXyhh
} MsBm0r`a
} =av0a!
;l1.jQh
8rx|7
//启动子线程 as'yYn8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `*elzW
for(int i=0;i<nStartPos.length;i++) ak-agH
{ [?hvx}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [Y~~C J
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), rB{w4
nStartPos,nEndPos,i); &4+|{Zx0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZyDNtX%
fileSplitterFetch.start(); }n "5r(*^@
} )t@9!V
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), alB'l
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); q7<d|s
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", OR*JWW[]
nEndPos = " + nFileLength); C/QmtT~`e
// fileSplitterFetch[nPos.length-1].start(); t|V<K^
&AOGg\
)0/*j]Kf
//等待子线程结束 mE5{)<N:C
//int count = 0; AorY#oq
//是否结束while循环 L N Fe7<y
boolean breakWhile = false; -EE'xh-zD
`U b*rOMu
W~2,J4=
while(!bStop) M^Y[Y@U=p
{ i39ZBs@
write_nPos(); <i4]qO(0u
Utility.sleep(500); /t< &
breakWhile = true; 2Wu`Dp;&l
[\#ANA"
Vfga%K%l F
for(int i=0;i<nStartPos.length;i++) y631;dU
{ R<Mc+{*>
if(!fileSplitterFetch.bDownOver) %8D>aS U
{ g1|Pyt{
breakWhile = false; oH+PlL
break; /Jc{aw
} 8nu!5 3
} qHp2;
if(breakWhile) 0O,;[l
break; Zs{7km
LSA6*Q51
b_ak@LYiu
//count++; UWEegFq*
//if(count>4) U65l o[
// siteStop(); :IBP "
} \O4s0*gw
]hS<"=oj
w|]Tt="
System.err.println("文件下载结束！"); *;9H\%
} vanV|O
catch(Exception e){e.printStackTrace ();} %qz-b.
} br Iz8]
fkp(M
QNINn>2
//获得文件长度 ['Lo8 [
public long getFileSize() &Z[+V)6,,
{ #h^nvRmON
int nFileLength = -1; (3mL!1\
try{ p<(a);<L
URL url = new URL(siteInfoBean.getSSiteURL()); zn 0y`9!n?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <Vk}U
httpConnection.setRequestProperty("User-Agent","NetFox"); @IsUY(Gu
= g &
t6\H
int responseCode=httpConnection.getResponseCode(); %hN>o)
if(responseCode>=400) kmC0.\
{ g%"SAeG<K
processErrorCode(responseCode); 6WQN!H8+^
return -2; //-2 represent access is error z[1uub,)1
} ?g{[U0)
\XmplG:
k kAg17 ^
String sHeader; {q`8+$Z;
>n3GvZ5%
] 1pIIX}
for(int i=1;;i++) p<H_]|7$7U
{ 1t^y?<)
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); x}pH'S7
//Utility.log(in.readLine()); G#e]J;
sHeader=httpConnection.getHeaderFieldKey(i); \t1#5
if(sHeader!=null) kJJiDDL0;*
{ MymsDdQ]
if(sHeader.equals("Content-Length")) o]4BST(A
{ &_-=(rK
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5I2 h(Td
break; '%t$mf!nV
} %;ED}X
} HBR/" m
else gEsD7]o(=
break; 8)eRm{
} U ->vk{v
} APF`b
catch(IOException e){e.printStackTrace ();} 6]%=q)oL[
catch(Exception e){e.printStackTrace ();} P8ej9ULX,
@}H'2V
MYvz%7
Utility.log(nFileLength); t2{(ETV
.eg'Z@o
*5BVL_:~J
return nFileLength; jd ;)8^7K
} Qc-W2%
}wn|2K'
?m2FN<S
//保存下载信息（文件指针位置） nw--
private void write_nPos() 4cSs=|m?+
{ !PGCoI
try{ {CR`~)v&
output = new DataOutputStream(new FileOutputStream(tmpFile)); qjkWCLOd
output.writeInt(nStartPos.length); }NwmZw>_
for(int i=0;i<nStartPos.length;i++) )e PQxx
{ Cj3Xp~
// output.writeLong(nPos); 9 c9$cnQ
output.writeLong(fileSplitterFetch.nStartPos); xjU0&
output.writeLong(fileSplitterFetch.nEndPos); hz;SDaBA
} `Zo5!"'
output.close(); jrN 5l1np
} #e-7LmO~
catch(IOException e){e.printStackTrace ();} c^1JSGv
catch(Exception e){e.printStackTrace ();} OfBWf6b
} aC1 xt(
89D`!`Ah]
3{co.+
//读取保存的下载信息（文件指针位置） =/|GWQj
private void read_nPos() =Xr{ Dg
{ ,e1c,}
try{ uGXvP(Pg'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); SGZYDxFC@
int nCount = input.readInt(); W`_Wi*z4
nStartPos = new long[nCount]; 3=ME$%f
nEndPos = new long[nCount]; rjcH[U(
for(int i=0;i<nStartPos.length;i++) XS@iu,uO
{ ?:60lCqj
nStartPos = input.readLong(); ;WN%tI)
nEndPos = input.readLong(); Ja*,ht(5
} >BO!jv!a
input.close(); cp8w _TPU
} tQ;Fgv8Y!
catch(IOException e){e.printStackTrace ();} st"@kHQ3
catch(Exception e){e.printStackTrace ();} OI)k0t^;D
} 0K^@P#{hd
D&mPYxXL
`{"V(YMEV
private void processErrorCode(int nErrorCode) AM!P?${a
{ av(qV$2
System.err.println("Error Code : " + nErrorCode); 7eM6 B#rI
} EMH-[EBx
EiM\`"o
~8k`~t!
//停止文件下载 6I=d0m.io
public void siteStop() gPKO-Fsd"
{ |Zn,|-iW
bStop = true; %iIr %P?
for(int i=0;i<nStartPos.length;i++) l@UF-n~[
fileSplitterFetch.splitterStop(); u_ :gqvC=
9} C(M?d
L)|hjpQ
} FN sSJU3ld
} U/U_q-z]
//负责部分文件的抓取 nrpbQ(zI*
**FileSplitterFetch.java /8_x]Es/
*/ p|;#frj
package NetFox; E?K(MT&@
tx1TtWo
2-g 5Gb2|
import java.io.*; d<\X)-"
import java.net.*; +BI%.A`2
5 YIk
<Vyl*a{%
public class FileSplitterFetch extends Thread { /*S6/#
}FV_jJ
'#lEUlB
String sURL; //File URL 3WkrG.$[b
long nStartPos; //File Snippet Start Position ,0Udz0
long nEndPos; //File Snippet End Position REJBm
int nThreadID; //Thread's ID }darXtZKkK
boolean bDownOver = false; //Downing is over }236{)DuN
boolean bStop = false; //Stop identical Pa\yp?({q
FileAccessI fileAccessI = null; //File Access interface G7-.d/8|^
W}(xE?9&
xWQQX
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException M _Lj5`
{ W7V#G(cpU
this.sURL = sURL; sDHFZ:W
this.nStartPos = nStart; `kOp9(Q{
this.nEndPos = nEnd; _3KfY
nThreadID = id; IU}g[OCu
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]tK<[8Y
} gavf$be
g( eA?
w~9Y=|YI7
public void run() [9CBTSr
{ +>mU4Fwp
while(nStartPos < nEndPos && !bStop) Z79Y$d>G<E
{ %.IW H9P7
|oOA;JC)(
d5LL( "
try{ [DSzhi]
URL url = new URL(sURL); J72kjj&C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]CnT4[f!
httpConnection.setRequestProperty("User-Agent","NetFox"); _B==S4^/yU
String sProperty = "bytes="+nStartPos+"-"; [QT H~
httpConnection.setRequestProperty("RANGE",sProperty); UUgc>
Utility.log(sProperty); ^j_t{h)W(0
PTA_erU
vN)l3
InputStream input = httpConnection.getInputStream(); QN~9O^
//logResponseHead(httpConnection); -Ze2]^#dl
-S$Y0FDV
8g_GXtn(z
byte[] b = new byte[1024]; /Q9iO&Vu
int nRead; @2A&eLwLH
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g9gyx/'*
{ Bd13p_V"6
nStartPos += fileAccessI.write(b,0,nRead); j=b-Y
//if(nThreadID == 1) ?0+J"FH# W
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?B4X&xf.D
} Fmrl*tr
H]f8W]"c[
M059"X="
Utility.log("Thread " + nThreadID + " is over!"); -S}^b6WL
bDownOver = true; Q S.w#"X[
//nPos = fileAccessI.write (b,0,nRead); Z2\Xe~{
} 4L6'4t"s
catch(Exception e){e.printStackTrace ();} 9fqCE619a
} z"@UNypc,
} 8nRxx`U\q
?)c9!hR
/kd6Yq(y
//打印回应的头信息 ud,_^Ul
public void logResponseHead(HttpURLConnection con) 0R?LWm j
{ ,#=;V"~9
for(int i=1;;i++) 2`/p V0
{ EtvYIfemr
String header=con.getHeaderFieldKey(i); =g^JJpS
if(header!=null) mt3j$r{_
//responseHeaders.put(header,httpConnection.getHeaderField(header)); G`R2=bb8
Utility.log(header+" : "+con.getHeaderField(header)); AqP7UL
else ]u O|YLWp
break; <NX6m|DD
} IY9##&c3>
} ZNbb8v
ulnlRx
PEAo'63$
public void splitterStop() T .L>PL?=
{ mOi 8W,2
bStop = true; {BJn9B
} J{5&L &4
GCA?sFwo>
|/35c0IM
} y 4jelg
SA16Ng
k39;7J
/* &!FWo@
**FileAccess.java s3l:ST
*//文件访问(定位，写) 1{X ;&y
package NetFox; mo3HUXf}8
import java.io.*; , 8F(R%v
ZzuWN&
B mxBbg
public class FileAccessI implements Serializable{ APucA
yY42+%P
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |nj,]pA
RandomAccessFile oSavedFile; wi/dR}*A
long nPos; |d8x55dk
:s OsG&y
iPPW_Q9x
public FileAccessI() throws IOException 2f$6}m'Ad
{ RBzBR)@5
this("",0); U: Q&sq8U
} VlQaT7Q
n~NOqvT <
a5xp[TlXn.
public FileAccessI(String sName,long nPos) throws IOException `[Xff24(eb
{ A5> ,e|
oSavedFile = new RandomAccessFile(sName,"rw"); |cE 69UFB
this.nPos = nPos; $>fMu
oSavedFile.seek(nPos); ^h@1tFF
} :|?nz$
WwM/M!98J
Ui`Z>,0sFi
public synchronized int write(byte[] b,int nStart,int nLen) (AnM_s
{ Xm2p<Xu8h
int n = -1; UjU*`}k3
try{ tZ]/?+1G
oSavedFile.write(b,nStart,nLen); }[OOkYF#r
n = nLen; zLiFk<G@Xi
} 7R=cxD&
catch(IOException e) -?$Hr\
{ z!GLug*j`
e.printStackTrace (); \L:;~L/
} -q.tU*xf'
)!&7XL[
oopACE>
return n; g"iLhm`L
} g0D(:_QXp:
,!s;o6|*y
\We\*7^E
} 8 3wa{m:
]%PQ3MT.
(E*eq-8
/* 4j'cXxo
**SiteInfoBean.java $*`=sV!r
*/ BM&.Tw|x
package NetFox; @;we4G5
czV][\5
T.sib&R
public class SiteInfoBean { *3A[C-1~.
?p8(Uc#73
67/&.d!
private String sSiteURL; //Site's URL OA_Bz"
private String sFilePath; //Saved File's Path 5:ZM-kZT
private String sFileName; //Saved File's Name ']hB_4v
private int nSplitter; //Count of Splited Downloading File Wb/q&o
Ty21-0F
X;I;CZ={
public SiteInfoBean() sacaL4[_<
{//nSplitter的缺省值为5 jz%%r Q(
//default value of nSplitter is 5 (gv1f
this("","","",5); A@X&dy
} .*N,x0B(
E K)7g~
VE<&0d<
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) m\88Etl@
{ o#-K,|-
sSiteURL= sURL; JEK6Ms;)A
sFilePath = sPath; R)3P"sGuN
sFileName = sName; rVx%"_'*-
this.nSplitter = nSpiltter; #mNM5(o
i%8I (F
w>:~Ev]
} ]e'Ol$3U9=
MHv2r
S'NZb!1+
public String getSSiteURL() X/_e#H0
{ w~eF0{h
return sSiteURL; QGYO{S
} ?X1vU0c
uj_ OWre
DA_[pR
public void setSSiteURL(String value) Sxrbhnx
{ 4,!S?:7
sSiteURL = value; G H N
} meHAa`
]E1aIt
Qo!/]\
public String getSFilePath() CF`tNA3fxm
{ d3fF|Wp1
return sFilePath; S(^*DV
} ]OE{qXr{
dsKEWZ =
3McBTa!
public void setSFilePath(String value) \>8"r,hG|
{ +1Ha,Ok
sFilePath = value; li4rK<O
} Ng?n}$g*
EROf%oaz=
T [ `t?,
public String getSFileName() Q7X6OFl?
{ &wbe^Wp
return sFileName; 7-"ml\z
} \$o!M1j
uFM]4v3
uUUj?%
public void setSFileName(String value) k#8,:B2
{ pm+_s]s,
sFileName = value; (c `t'e
} pJC@}z^cw
PK#; \Zw
_7(>0GY
public int getNSplitter() aHosu=NK
{ Ctpr.
return nSplitter; #%4-zNS
} jg]_'^pVzr
[:x^ffs
gdupG
public void setNSplitter(int nCount) / vI sX3v
{ JG xuB*}
nSplitter = nCount; PiMW29B^
} PpPg ~ix*
} #/NZ0IbHk
VC "66\d&
eeX^zaKl]
/* }(h_ztw
**Utility.java >t|u 8/P
*/ =.9L/74@
package NetFox; Xqt3p6
uXiAN#1
<StyO[
public class Utility { G992{B
!/W[6'M#p
*ip2|2G$
public Utility() 8=rD'*
{ e_Na_l]
EQDsbG0x
c"w}<8
} [hs_HYqJ
_&TA|Da
//线程睡眠 %./vh=5)
public static void sleep(int nSecond) pqmS w
{ UPs*{m
try{ ?{W@TY@S
Thread.sleep(nSecond); 29DYL
} -lr)z=})
catch(Exception e) eMk?#&a)
{ D9 ~jMcX
e.printStackTrace (); 8_8r{a<xW
} 8X":,s!
} ;Wa4d`K
V)M+dhl
//日志 Q}p+/-U\
public static void log(String sMsg) }D_h*9
{ ~|e?@3_G
System.err.println(sMsg); RG [*:ReB9
} %N#8D<ULd
Ek|#P{!
>p4#AfGF
public static void log(int sMsg) M>+FIb(
{ &kKopJH
System.err.println(sMsg); 6/^$SWd2
} iaAVGgA9+
} gUf-1#g4\`
^vXMX^*
}gQ FWT
/* Xx_v>Jn!
**TestMethod.java Y!e
*/ 0|<ER3xkx
package NetFox; vzl+0"
tu}AJ
uMl.}t2uYu
public class TestMethod { *I)oDq3
(uV~1
Jh2eo+/%
public TestMethod() _=9o:F
{ ///xx/weblogic60b2_win.exe FB{4& ;
try{ vL"U=Q+/eY
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); QAYhAOS|e
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); pI2g\cH>
SiteFileFetch fileFetch = new SiteFileFetch(bean); LaL.C^K
fileFetch.start(); N S*e<9
} &z[39Q{~
catch(Exception e){e.printStackTrace ();} NF`WA-W8@
?I{pv4G:
]O'dwC
} H^cB?i
nN!/
Kbjt CI7
public static void main(String[] args) CR*R'KX D%
{ EgO=7?(pW
new TestMethod(); Hn"xn79nc
} __HPwOCG7
} e;KZTH;
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