社区应用 最新帖子 精华区 社区服务 会员列表 统计排行 社区论坛任务 迷你宠物
  • 12009阅读
  • 0回复

http断点续传简单实现(java)

发帖
8
铜板
1641
人品值
95
贡献值
0
交易币
0
好评度
8
信誉值
0
金币
0
所在楼道
/* Xe<kdB3  
**SiteFileFetch.java -|/*S]6kK  
*/ C )+%9Edg  
package NetFox; C'fQ Z,r-v  
import java.io.*; rJc=&'{&)N  
import java.net.*; X6EnC57  
fBct%M 3  
B7nm7[V  
public class SiteFileFetch extends Thread { z]=jer  
P<IZ%eS3B  
EL1*@  
SiteInfoBean siteInfoBean = null; //文件信息Bean  uE3xzF  
long[] nStartPos; //开始位置 *^.OqbO[U  
long[] nEndPos; //结束位置 _qq>-{-Ym  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Ia*T*q Ju  
long nFileLength; //文件长度 5*r5?ne  
boolean bFirst = true; //是否第一次取文件 n.xOu`gj  
boolean bStop = false; //停止标志 ,HfdiGs}j  
File tmpFile; //文件下载的临时信息 +&8'@v$  
DataOutputStream output; //输出到文件的输出流 !i?aRI/6  
6YYDp&nqEj  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) j'nrdr6n  
public SiteFileFetch(SiteInfoBean bean) throws IOException ? ]hS^&  
{ ;2iDa  
siteInfoBean = bean; Mg=R**s1x%  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 5q{ -RJ  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 6ragRS/'x  
if(tmpFile.exists ()) t-$Hti7Lk  
{ n_46;lD  
bFirst = false; dmUa\1g#  
read_nPos(); MnD^jcx   
} #=aTSw X  
else '| bHu  
{ XF Wo"%}w  
nStartPos = new long[bean.getNSplitter()]; hwd{^  
nEndPos = new long[bean.getNSplitter()]; </)QCl'd  
} *|&&3&7  
*aS[^iX?s  
x @uowx_&m  
AWz|HF#-  
} ,ko0XQBl  
nSeb?|$D6  
w.R2' W R  
public void run() qJT|om L Y  
{ wGAeOD  
//获得文件长度 H(F9&6}  
//分割文件 s. jcD  
//实例FileSplitterFetch <l"rnM%  
//启动FileSplitterFetch线程 5u&hp  
//等待子线程返回 vON1\$bu `  
try{ 4#2iq@s  
if(bFirst) 299uZz}Y  
{ $' >|r]  
nFileLength = getFileSize(); +}.S:w_xQ  
if(nFileLength == -1) 8VR! Y0`e  
{ \:`-"Ou(*  
System.err.println("File Length is not known!"); V.Qy4u7m  
} b?%Pa\,!  
else if(nFileLength == -2) _"'0^F$I  
{ F@Cxjz  
System.err.println("File is not access!"); 73>Hzpv0  
} &1,{.:@e  
else LXx`Vk>ky  
{ 7F 1nBd  
for(int i=0;i<nStartPos.length;i++) t[Ywp!y[  
{ XI58Cy*!  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 2RC@Fu~zaU  
} Kzf^ras4u  
for(int i=0;i<nEndPos.length-1;i++) j`ybzG^  
{ bx=9XZ9g  
nEndPos = nStartPos[i+1]; dEG1[QG  
} D./3,z  
nEndPos[nEndPos.length-1] = nFileLength; mM)d`br  
} DS6g_SS3  
} R\,qL-Br  
o `}(1$a>  
ZRLS3*`  
//启动子线程 8/`ij?gn  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; mZ}C)&,m2  
for(int i=0;i<nStartPos.length;i++) ~k780  
{ pQ yH`  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(),  njg\y  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &1$|KbmV4  
nStartPos,nEndPos,i); fVx_]5jM  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); XD$;K$_7  
fileSplitterFetch.start(); UJhUb)}^  
} JWo).  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U((mOm6  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [3fmhc  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", LQ3J$N  
nEndPos = " + nFileLength); o`<ps$ yT  
// fileSplitterFetch[nPos.length-1].start();  D/]  
)G=hgqy  
Ki(  
//等待子线程结束 HA0Rv#p  
//int count = 0; gtlyQ _V  
//是否结束while循环 VAet!H+]  
boolean breakWhile = false; vfPIC!  
]iE) 8X  
@'fWS^ ;&  
while(!bStop) \:|"qk  
{ KW-g $Ma  
write_nPos(); 2V)qnMxAZJ  
Utility.sleep(500); `=JGlN7  
breakWhile = true; !@wG22iC4d  
Bl!R bh\  
u RPvo}!=1  
for(int i=0;i<nStartPos.length;i++) XVWVY}  
{ -G@:uxB  
if(!fileSplitterFetch.bDownOver) B[B(=4EzMP  
{ d gRTV<vM  
breakWhile = false; I4\ c+f9  
break; YqNI:znm-  
} _ !H8j/b  
} 3}25=%;[  
if(breakWhile) fZF.eRP '  
break; 8PtX@s43\  
>a$b4 pvh  
p4M7BK:nf  
//count++; I^itlQ  
//if(count>4) WuUT>om H  
// siteStop(); C3GI?| b  
}  3JcI}w  
?Y | *EH  
A!.* eIV|  
System.err.println("文件下载结束!"); VaLl$w  
} <Z^qBM  
catch(Exception e){e.printStackTrace ();} SlojB^%  
} V07? sc<  
)*I%rN8b   
]n$&|@  
//获得文件长度 k}$k6Sr"  
public long getFileSize() n9x&Ws;  
{ bdz&"\$X  
int nFileLength = -1; gt{$G|bi  
try{ |cd=7[B  
URL url = new URL(siteInfoBean.getSSiteURL()); @!:_r5R~N  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KM jnY2  
httpConnection.setRequestProperty("User-Agent","NetFox"); bk{.9nz2  
%2t#>}If!  
H]d'#1G  
int responseCode=httpConnection.getResponseCode(); oq3{q  
if(responseCode>=400) ~sUWXw7~  
{ 9HJA:k*k|  
processErrorCode(responseCode); Z5%TpAu[  
return -2; //-2 represent access is error _rjLCvv-  
} 2-!n+#Cdf  
1?5UVv_F  
jFThW N  
String sHeader; xFy%&SKHg  
lM'yj}:~  
/'g"Ys?3  
for(int i=1;;i++) $,L,VYN  
{ {%Ujp9i  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); dgsD~.((A  
//Utility.log(in.readLine()); |`i.8  
sHeader=httpConnection.getHeaderFieldKey(i); KQ\d$fX  
if(sHeader!=null) 9}DF*np`G  
{ .ugQH<B  
if(sHeader.equals("Content-Length")) =gb(<`{>  
{ Y^P'slY{%  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); L.M|o  
break; e:H9!  
}  ;%tu;  
} +HxL>\  
else NDaM;`  
break; _$Hx:^p:  
} 70&]nb6f  
} fW'U7&O  
catch(IOException e){e.printStackTrace ();} , BCo/j  
catch(Exception e){e.printStackTrace ();} ;r}>1LhN  
~0~f  
U%,N"]`  
Utility.log(nFileLength); wRi` L7  
u/8urxp y  
&^W91C?<6  
return nFileLength; umo@JWr  
} _^)<d$R<  
;Pi-H,1b  
w 9mi2=  
//保存下载信息(文件指针位置) A+Xk=k5<  
private void write_nPos() k)a-odNrb  
{ B "z`X!\  
try{ l[EjtN  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?]# U~M<'  
output.writeInt(nStartPos.length); i@C$O.m(  
for(int i=0;i<nStartPos.length;i++) IO\ >U(:vx  
{ lV0\UySH  
// output.writeLong(nPos); uM^eoh_  
output.writeLong(fileSplitterFetch.nStartPos); u0(PWCi2  
output.writeLong(fileSplitterFetch.nEndPos); 1E*No1  
} kr C4O2Fkj  
output.close(); .#] V5g,  
} x1}7c9n K  
catch(IOException e){e.printStackTrace ();} URodvyD  
catch(Exception e){e.printStackTrace ();} (IXe5 55  
} M=hH:[6 &  
d,G:+  
wf<=r W'  
//读取保存的下载信息(文件指针位置) KnC;j-j  
private void read_nPos() Eo$7W5h J  
{ L]goHs  
try{ 65ctxxWv1  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); gqje]Zc<  
int nCount = input.readInt(); E,[@jxP  
nStartPos = new long[nCount]; E-\<,=bh  
nEndPos = new long[nCount]; $EB&]t+  
for(int i=0;i<nStartPos.length;i++) -o8H_MR  
{ Z. ))=w6G  
nStartPos = input.readLong(); 3K/32Wi  
nEndPos = input.readLong(); e `!PQMLU  
} `N_elf://n  
input.close(); ' {L5 3cH=  
} (hB&OP5Fne  
catch(IOException e){e.printStackTrace ();} 3Ms ` ajJ  
catch(Exception e){e.printStackTrace ();} H+`s#'(i_P  
} b3G4cO;t;  
gNdEPaaFI  
I6x  
private void processErrorCode(int nErrorCode) p9;Oe,Il  
{  fWx %?J  
System.err.println("Error Code : " + nErrorCode); +0016UgS#  
} d;3/Vr$t=  
W)dQ yZ>J  
B&~#.<23:  
//停止文件下载 8IYn9<L  
public void siteStop() 3[g%T2&[  
{ 9Ij=~p]p  
bStop = true; [*<F   
for(int i=0;i<nStartPos.length;i++) 4!pMZ<$3  
fileSplitterFetch.splitterStop(); M^c`j#NQ  
c/Fy1Lv\  
la7VeFT  
} T5; zgr  
} jN\} l|;q  
//负责部分文件的抓取 $TON`+lB  
**FileSplitterFetch.java gOpi>  
*/ ,m| :U  
package NetFox; 4l/hh|3@  
M ABrf`<b  
p5|.E  
import java.io.*; G%{J.J41F  
import java.net.*; :.863_/  
4K_rL{s0U  
l<5@a (  
public class FileSplitterFetch extends Thread { Arg604V3  
uhi(Gny.  
9yU(ei:GUo  
String sURL; //File URL J1@X6U!{  
long nStartPos; //File Snippet Start Position <L4.*  
long nEndPos; //File Snippet End Position YP*EDb?f  
int nThreadID; //Thread's ID {MP8B'r-6  
boolean bDownOver = false; //Downing is over r5U[jwP  
boolean bStop = false; //Stop identical 3uSj5+@q6  
FileAccessI fileAccessI = null; //File Access interface Tm!pAD  
?b?6/_W~R  
S$ u`)BG):  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException nQe^Bn  
{ @>>8CU^~  
this.sURL = sURL; 7jss3^.wA  
this.nStartPos = nStart; BE`{? -G  
this.nEndPos = nEnd; %w+"MkH _  
nThreadID = id; [BPK0  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 W7bA#p(  
} v|IPus|>  
q"Ct=d  
7R4sd  
public void run() Z~&$s  
{ N_ 3$B=  
while(nStartPos < nEndPos && !bStop) \"L ;Ct 8  
{  rG#o*oA  
MIV<"A  
6j*L]S c  
try{ ^^q9+0@  
URL url = new URL(sURL); D8Ntzsr6  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R,]J~TfPK  
httpConnection.setRequestProperty("User-Agent","NetFox"); ,\YlDcl':0  
String sProperty = "bytes="+nStartPos+"-"; D<V[:~-o  
httpConnection.setRequestProperty("RANGE",sProperty); qDG{hvl[1r  
Utility.log(sProperty);  fP+RuZ  
mEL<d,XhI  
JQi+y;  
InputStream input = httpConnection.getInputStream(); d-GU164  
//logResponseHead(httpConnection); ^("23mhfJ  
Z2Q'9C},m  
rM?O2n  
byte[] b = new byte[1024]; i5PZ)&  
int nRead; = aO1uC|6C  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3 pzp6o2  
{ Fe r&X  
nStartPos += fileAccessI.write(b,0,nRead); BM~>=emc  
//if(nThreadID == 1) A_8UPGh8  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /Bt+Ov3k  
} x9DG87P~+  
%S`ygc}|  
N7Kg52|  
Utility.log("Thread " + nThreadID + " is over!"); sJI" m'r=Z  
bDownOver = true; AVn?86ri  
//nPos = fileAccessI.write (b,0,nRead); M%yeI{m  
} 4Nb&(p  
catch(Exception e){e.printStackTrace ();} 0A,u!"4[  
} TnuaP'xZ  
} =c(t;u6m-  
!iNN6-v%  
!t;B.[U *  
//打印回应的头信息 sYfiC`9SO  
public void logResponseHead(HttpURLConnection con) /8cfdP Ba  
{ o4.?m6d  
for(int i=1;;i++) =<BPoGs5  
{ Th'B5:`  
String header=con.getHeaderFieldKey(i); dmB _`R  
if(header!=null) nB|m!fi<  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5bj9S  
Utility.log(header+" : "+con.getHeaderField(header)); Eo) #t{{  
else ln1QY"g  
break; 9}*Pb6  
} 3D}rxI8N  
} Il4R R  
Md*~hb8J  
)yTBtYw3  
public void splitterStop() *3!#W|#=]N  
{ 2Wx~+@1y  
bStop = true; ^~7/hm:  
} -d*zgP  
7l+:gD  
WV8vDv1jt  
} DtFzT>$^F  
XU*4MU^'  
(i.7\$4  
/* #dj,=^1_14  
**FileAccess.java W<c95QD.  
*//文件访问(定位,写) Gbwq rH+  
package NetFox; NI^jQS M]  
import java.io.*; FoX,({*Ko~  
%7v!aJ40  
7L4~yazmK  
public class FileAccessI implements Serializable{ 5OM*NT t  
K/l*Saj  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 th^&wp  
RandomAccessFile oSavedFile; DedY(JOvB  
long nPos; 4(%LG)a4S  
OnND(YiX  
\sEH)$R'  
public FileAccessI() throws IOException `gX$N1(  
{ IJk<1T7:(W  
this("",0); DyCnL@  
} :>*0./hG  
0..]c-V(G  
F T$x#>  
public FileAccessI(String sName,long nPos) throws IOException Vv_lBYV  
{ .L8g( F(=:  
oSavedFile = new RandomAccessFile(sName,"rw"); S7h?tR*u  
this.nPos = nPos; >*h3u7t  
oSavedFile.seek(nPos); 43s8a  
} ~[Z,:=z  
 jAxrU  
/ _! Ed]  
public synchronized int write(byte[] b,int nStart,int nLen) @ruWnwb  
{ y1bo28  
int n = -1; PlRcrT"#w  
try{ V)Ze> Pp  
oSavedFile.write(b,nStart,nLen); Lk]W?  
n = nLen; Nz%Yi?AF  
} /wPW2<|"X.  
catch(IOException e) B&"c:)1 C2  
{ 6B!v;93U  
e.printStackTrace (); 7_~_$I~g*  
} -u^f;4|u  
4Cp)!Bq?/  
X@\ 9}*9  
return n; UgTgva>?  
} v!j%<H`NI  
C#@-uo2  
}=fls=c/0  
} Ge ?Q)N  
cuh Z_l  
Sr>5V  
/* J]5ZWo%  
**SiteInfoBean.java ,0aRHy_^  
*/  tPChVnB  
package NetFox; D77s3AyHK  
b!T-{Ns6  
e3WEsD+  
public class SiteInfoBean { T:3}W0s,  
" ""pe+Y  
h$#|s/  
private String sSiteURL; //Site's URL o('6,D  
private String sFilePath; //Saved File's Path Tbj}04;I  
private String sFileName; //Saved File's Name vlo!D9zsV3  
private int nSplitter; //Count of Splited Downloading File Ga\kvMtr  
J@qwz[d i  
U nS|""  
public SiteInfoBean() ,[[Xo;q  
{//nSplitter的缺省值为5 LY2QKjgP  
//default value of nSplitter is 5 xiO10:L4  
this("","","",5); @c=bH>Oz  
} w" Y'I$  
NdB:2P  
"QmlW2ysi  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) zYEb#*Kar  
{ GpCjoNcW{  
sSiteURL= sURL; A\v]ZN4  
sFilePath = sPath; >NZJ-:t  
sFileName = sName; MPMAFs  
this.nSplitter = nSpiltter; >2mV {i&  
Bp/25jy  
\9 k3;zw  
} !H(V%B%  
[_HOD^  
^-,@D+eW  
public String getSSiteURL() 8@]vvZ2/gj  
{ P9M. J^<  
return sSiteURL; R(IYb%L  
} Jp(CBCG{F  
*z__$!LR  
}^azj>p5  
public void setSSiteURL(String value) zd3^k<  
{ T&->xe f=  
sSiteURL = value; R_Uy.0=4  
} uHPd!# ]  
Hx NoV.q  
w~>tpkUB  
public String getSFilePath() ]%+T+ zg(Y  
{ :_kZkWD5  
return sFilePath; z0?IQzR^T  
} vA*Q}]Ov  
;]_h")4"c  
KVPWJHGr  
public void setSFilePath(String value) z)%]# QO  
{ 2I{kLN1TY  
sFilePath = value; ]\*_}  
} $t.M `:G  
Nq#B4Zx  
`{xKU8j^  
public String getSFileName() rV B\\  
{ a&<_M$J&  
return sFileName; FBS]U$1  
} 0HDL;XY6  
qD{~QHDa  
n"f: 6|<  
public void setSFileName(String value) QZFH>,d  
{ TnJNs  
sFileName = value; af|x(:!H  
} "8/BVW^bv  
wS+j^ ;"  
6@Ir|o  
public int getNSplitter() fzzk#jU  
{ L4v26*P  
return nSplitter; ?4#wVzuzA  
} U|+ c&TY  
O#Ho08*Xn  
a=M/0N{!  
public void setNSplitter(int nCount) YA~`R~9d  
{ 9]QHwa>_|2  
nSplitter = nCount; kn}bb*eZ  
} 3Hf_!C=g  
} r>J%Eu/O  
mLDuizWI  
G|qsJ  
/* =J'&.@Dwz  
**Utility.java 'k/:3?R  
*/ $~NB .SY  
package NetFox; *z)+'D*+  
pV/5w<_x?  
X- `PF  
public class Utility { vPD%5 AJN  
Ys8D|HIk  
H6<3'P  
public Utility() Z5,"KhB]  
{ *|6*jU  
K9) |b`E=  
IgPU^?sp  
} >Zh^,T={G  
vGchKN~_  
//线程睡眠 ,D\}DJ`)C  
public static void sleep(int nSecond) M2LW[z  
{ D;6C2>U~L  
try{ .J \i!  
Thread.sleep(nSecond); 3V3q vd  
} cQ(,M  
catch(Exception e) w exa\o  
{ !r4B1fX  
e.printStackTrace (); /@@?0xjX  
} ]P)2Q!X  
} @*iT%p_L  
lhB;jE  
//日志 ORFi0gFbA  
public static void log(String sMsg) #=#bv`  
{ C^*}*hYk$  
System.err.println(sMsg); 8" (j_~;  
} )Tw A?kj  
W/u_<\  
tD6ukK1x  
public static void log(int sMsg) Xuj=V?5  
{ 6yXN7L==x  
System.err.println(sMsg); +5H1n(6)  
} ,AG k4]  
} `2n%Lo?_  
(} Y|^uM,  
&"clBR Vg  
/* _ _[bKd.  
**TestMethod.java A#nSK#wS61  
*/ .cs4AWml<  
package NetFox; 0">9n9  
vxXrVPU3  
CW?R7A/  
public class TestMethod { LNM#\fb  
x{1S!A^  
O]G3l0  
public TestMethod() K.42 VM)F  
{ ///xx/weblogic60b2_win.exe pI}6AAs}Z  
try{ N`+@_.iBX  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i?6#>;f  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); x, #?  
SiteFileFetch fileFetch = new SiteFileFetch(bean); T 5>'q;jM  
fileFetch.start(); \!zM4ppr  
} \6vr)1~N>  
catch(Exception e){e.printStackTrace ();} tfPe-U  
\8/$ZEom  
M ~5Ja0N~  
} j~#v*qmDU  
t?h\Af4Tf  
5N$O  
public static void main(String[] args) '(SqHP|8&g  
{ i(0%cNP7  
new TestMethod(); ML:H\  
} R'h.lX  
} W!)B%.Q  
点击下载更多相关资料
评价一下你浏览此帖子的感受

精彩

感动

搞笑

开心

愤怒

无聊

灌水
描述
快速回复

您目前还是游客,请 登录注册
如果您在写长篇帖子又不马上发表,建议存为草稿
认证码:
验证问题:
3+5=?,请输入中文答案:八 正确答案:八